Reproductive factors and breast cancer risk in Palestine: A case control study

BackgroundEarly age at menarche, late age at menopause, and late age at first full-term pregnancy are linked to a modest increase in the risk of developing breast cancer (breast ca). This study aims to investigate the reproductive determinants of breast cancer among women in the West Bank of Palestine.A structured questionnaire was used to collect data in a case-control study (237 registered cases and 237 controls). A multivariate analysis model was used to adjust for the association between women’s reproductive factors and breast ca risk. This study was approved by Al Quds University Ethical Research Committee and the Ministry of Health research unit.ResultsIn the multivariate analysis, menarche after 13 years of age, use of oral contraceptives for more than two months, and hormonal contraceptives use significantly doubled the risk for breast ca (Adjusted Odds Ratio (AOR) = 2.03, 95 % CI: 1.21–4.37, p < 0.011 and AOR = 2.2, 95 % CI: 1.24–4.01, p = 0.008, respectively). Women who used hormone replacement therapy (HRT) were significantly associated with higher odds (5 folds) of having breast ca versus those who did not use them (AOR 5.02, 95 % CI: 1.93–13.06, p = 0.001). Similarly, nulliparous women showed 6 times the odds of breast ca compared with women with one or more children (p = 0.005). Also, parental consanguinity marriage (AOR 2.59, 95 % CI: 1.53–4.36, p = 0.001) and positive family history (AOR 3.88, 95 % CI: 2.19–6.87, p = 0.001) of the condition can be strong determinants for breast ca in this study.ConclusionThis study provides clear evidence that the use of reproductive hormones, whether as a birth control tool or for therapeutic purposes, must be rationalized worldwide and in Palestine in particular.     

Breast cancer susceptibility loci in association with age at menarche,age at natural menopause and the reproductive lifespan

Background: Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) associated with breast cancer risk. Some of these loci have unknown functional significance and may mediate the effects of hormonal exposures on breast cancer risk. We examined relationships between breast cancer susceptibility variants and menstrual/reproductive factors using data from two population-based studies. Methods: The first analysis was based on a sample of 1328 women age 20–74 who participated as controls in a case–control study of breast cancer conducted in three U.S. states. We evaluated the associations between age at menarche, age at natural menopause and the reproductive lifespan with 13 previously identified breast cancer variants. Associations were also examined with a genetic score created as the sum of at-risk alleles across the 13 variants. For validation, significant results were evaluated in a second dataset comprised 1353 women age 43–86 recruited as part of a cohort study in Wisconsin. Results: Neither the genetic score nor any of the 13 variants considered individually were associated with age at menarche or reproductive lifespan. Two SNPs were associated with age at natural menopause; every increase in the minor allele (A) of rs17468277 (CASP8) was associated with a 1.12 year decrease in menopause age (p = 0.02). The minor allele (G) of rs10941679 (5p12) was associated with a 1.01 year increase in age at natural menopause (p = 0.01). The results were not replicated in the validation cohort (B = −0.61, p = 0.14 and B = −0.01, p = .0.98, respectively). Conclusions: The evaluated variants and reproductive experiences may work through separate pathways to influence breast cancer risk.     

Reproductive factors and breast cancer risk among BRCA1 or BRCA2 mutation carriers: Results from ten studies

Although reproductive factors are among the most well-established risk factors for breast cancer in the general population, it is still a matter for debate whether these factors act as risk modifiers among BRCA1 or BRCA2 mutation carriers. This meta-analysis is the first to be performed to determine the relationship between reproductive factors and breast cancer risk among BRCA1 and BRCA2 mutation carriers. We searched the PubMed database up to February 2013. A total of ten studies met the inclusion criteria. The results showed that the reproductive factors may be associated with breast cancer risk only among BRCA1 mutation carriers. No association was found between parity and breast cancer risk. Compared with women at the youngest age in the first-birth category, women in the oldest age category were at a 38% lower risk of breast cancer (RR = 0.62, 95%CI = 0.45–0.85). Breastfeeding for at least 1 or 2 years was associated with a 37% reduction in breast cancer risk (RR = 0.63, 95%CI = 0.46–0.86). Women at the oldest age in the menarche category were at a 34% lower risk of breast cancer (RR = 0.66, 95%CI = 0.53–0.81) than women in the youngest age category. However, none of the reproductive factors were associated with breast cancer risk among BRCA2 mutation carriers. In conclusion, late age at first birth, breastfeeding, and late age at menarche protect against breast cancer in BRCA1 mutation carriers only. Further studies are needed to explore the mechanisms.     

Hormonal aspects in the causation of human breast cancer: epidemiological hypotheses reviewed, with special reference to nutritional status and first pregnancy

Epidemiology of breast cancer has identified early age at menarche, late first pregnancy, low parity and late menopause as risk factors, but in addition genetic factors, height, weight and living in western countries play a significant role. The international variation in incidence is almost exclusively due to non-genetic factors. Hypotheses in prevention-oriented research are reviewed: 1. obesity-related oestrogen production as a stimulus of the tumour in postmenopausal women; 2. nutritional status and energy expenditure during puberty and adolescence, developed for fertility and fecundity and extended later to breast cancer; 3. reproductive life during early adulthood, age at first pregnancy and its specific effects on breast tissues. The message of preventability of breast cancer is that mammary epithelial differentiation should come early. Our insight concerning events in puberty and early adulthood can be consolidated in one concept on the risk of extended proliferation of breast epithelium during early adulthood in the absence of full differentiation induced by pregnancy. The combined effects of Western-type nutrition, lack of exercise and Western-type women's emancipation sets the stage for breast cancer already at a young age. Since it is unlikely that emancipated women in affluent societies will return to the original life-style of getting pregnant as soon as it is biologically possible, a novel daring way of protection has to be considered. Could a "Breast Differentiation Pill" be developed to offer protection?     

The evolutionary history of childbirth

Consideration of the evolutionary and cross-cultural history of childbirth reveals many differences between the ways in which most human females have experienced childbirth and the ways in which most women in contemporary industrialized obstetric settings experience the event. In this paper I review two of these differences: the pain and anxiety of labor and delivery and the discontinuity of care provided for the mother and infant. I argue that much of the dissatisfaction with birth practices in the United States results from the failure of modern obstetric practice to meet the evolved needs of mothers and infants. Wenda Trevathan is an associate professor of anthropology at New Mexico State University. Her research interests focus on evolutionary and biosocial aspects of human female reproductive behavior, including childbirth, sexuality, and menopause. She is the recipient of the 1990 Margaret Mead Award and has received midwifery training.     

A critique of Darwinian anthropology

Darwinian anthropology holds that human behavior is adaptive in the sense of being designed to maximize reproductive success and that measurement of reproductive differentials typically illuminates adaptation. I argue to the contrary, that adaptive design is usually manifested at the psychological rather than at the behavioral level, that measuring reproductive differentials is at best an inefficient and ambiguous way to illuminate adaptation, and that Darwin's theory of natural selection sheds light on human affairs only insofar as it promotes understanding of the psychology that underpins these affairs.     

Effect of household structure on female reproductive strategies in a Caribbean village

Household structure may have strong effects on reproduction. This study uses household demographic data for 59 women in a Caribbean village to test evolutionary hypotheses concerning variation in reproductive strategies. Father-absence during childhood, current household composition, and household economic status are predicted to influence age at first birth, number of mates, reproductive success, and pair-bond stability. Criterion variables did not associate in a manner indicative of r- and K-strategies. Father-absence in early childhood had little influence on subsequent reproduction. Household wealth and alloparenting were positively associated with age at first birth. Alloparenting was negatively associated with reproductive success. Women in long-term conjugal unions had higher reproductive success than did single women. Number of adult male kin resident in the household was negatively associated with women’s number of mates. This research was funded by NSF grants (BNS 8920569 and SBR 9205373) to Mark Flinn and an Earthwatch Center for Field Research grant to Mark Flinn, Robert Quinlan, and Marsha Quinlan. Robert Quinlan is currently an assistant researcher at the Research Corporation of the University of Hawai’i. He has a Ph.D. in Anthropology from the University of Missouri. His research interests include human evolutionary ecology, household demography, and biomedical anthropology.     

Endogenous oestrogens and breast cancer risk in premenopausal and postmenopausal women

Breast cancer risk is strongly related to several reproductive and hormonal factors, but the nature of the effects of endogenous oestrogens has been difficult to establish. Data are now available from several large prospective studies with biobanks of stored serum, enabling better characterization of the associations of endogenous oestrogens, and other endogenous hormones, with breast cancer risk. In postmenopausal women, relatively high serum concentrations of oestradiol are associated with a more than twofold increase in the risk for breast cancer, and this probably explains the increase in risk in obese postmenopausal women. In premenopausal women the data available on oestrogens are more limited and difficult to interpret due to the large variations in endogenous oestrogens during the menstrual cycle, but are compatible with a positive association between oestradiol and breast cancer risk. There is also evidence that breast cancer risk is positively associated with androgens, prolactin and insulin-like growth factor-I. Further data are required, with better assays and repeat measures, to provide more accurate estimates of risk and to clarify the role of oestrogens in premenopausal women and the roles of other endogenous hormones.     

Female sexual advertisement reflects resource availability in twentieth-century UK society

Evolutionary theory suggests that men and women differ in the characteristics valued in potential mates. In humans, males show a preference for physical attractiveness, whereas females seek cues that relate to resources and future earning potential. If women pursue marriage as an economic strategy, female sexual advertisement should increase during periods of poor economic conditions when the number of high-quality male partners becomes a limited resource. To test this prediction, measures of skin display and clothing tightness were taken for clothes portrayed in UK Vogue magazine from 1916 to 1999. These estimates of sexual advertisement were analyzed in relation to an index of economic prosperity (GDP), while controlling for general increases in economic conditions and sexual display over the course of the past century. The results indicate that female sexual display increases as economic conditions decline, with the level of breast display and the tightness of clothing at the waist and hips the key factors underlying this increase. Breast size and symmetry and female body form are secondary sexual characteristics that play an important role in sexual attractiveness. Since advertisement of these features increases as levels of competition for high-quality partners increases, females appear to use marriage as an economic strategy. Patterns of female fashion appear to be underpinned by evolutionary considerations relating resource availability to female reproductive success. Russell Hill, B.Sc., M.Phil., Ph.D. is an Addison Wheeler Research Fellow at the University of Durham. His main research interests are in the evolution of mammalian social systems and his current projects span evolutionary anthropology, conservation biology, and theoretical modeling. Sophie Donovan B.Sc., M.Sc. has recently completed an M.Sc. in Speech and Language Sciences at University College London, focusing on the development of a deaf child’s vocabulary through conversations in the classroom. She is currently practicing as a Speech and Language Therapist. Nicola Koyama, B.Sc., Ph.D. is a Senior Lecturer at Liverpool John Moores University. Her principal research interests lie in the evolution of social systems in human and non-human primates, in particular the regulation of social relationships, mate preferences, and conflict management.     

Prospective breast cancer risk factors prediction in Saudi women

Women's health is affected by breast cancer worldwide and Saudi Arabia (SA) is no exception. Malignancy has enormous consequences for social, psychological and public health. The aim of this study was to examine the risk factors for Saudi women from breast cancer using logistic regression models. In 135 patient cases for different stages of breast cancer was used to study case management, 270 healthy women from King Abd Alla Medical City, Mecca, SA were taken to predict the probability of women developing breast cancer, logistic regression was analyzed taking factors such as age, marital status, family history, parity, age at first full-term pregnancy, menopausal status, body mass index (BMI) and breast feeding. The logistic regression model showed that there are important risk factors (age, marital status, family history, parity, age at first full-term pregnancy, menopausal status, body mass index, and breast feeding) in development of breast cancer. Fewer cases were observed in unmarried women, age ≤30, BMI ≤20. In contrast, more cases were found with women age 41–50 married, BMI > 30, a smaller number of children, not breast feeding, age of first pregnancy ≥30, menopausal status age at 46–50. Based on our data there is role of risk factors in developing breast cancer, less BMI, the increase number of children, breast feeding, which are playing as protective factor for breast cancer.     

The Relationship of Body Mass Index to Reproductive Factors in Pre- and Postmenopausal African-American Women With and Without Breast Cancer

To date, there are virtually no existing data on the relationship between obesity, menopausal status, and breast cancer in African-Americans. Therefore, the present study was designed to test the following hypotheses in an African-American population: (1) there exists a positive association between BMI and breast cancer among postmenopausal women; (2) there exists an inverse association between BMI and breast cancer among premenopausal women; and (3) similar associations between BMI and reproductive factors exist for both pre- and postmenopausal breast cancer cases. The study population comprised 357 African-American women (n=193 breast cancer cases; n=164 controls). No significant differences were observed between premenopausal cases and controls for BMI, obesity categories, and reproductive factors. Among the postmenopausal women, the cases had significantly lower weight and BMI levels than the controls. Age at first pregnancy and parity were significantly lower among postmenopausal cases than their controls. No significant associations were revealed between body mass index and breast cancer for pre- and postmenopausal women. In the present study, early age at menarche was the only reproductive factor that was an independent predictor of BMI for both pre- and postmenopausal women, irrespective of breast cancer status. Also, these findings strongly suggest the need to consider reproductive factors, particularly age at menarche, as a covariate of BMI and other obesity-related diseases.     

Duration of ovarian hormone exposure and gynecological cancer risk in Korean women: the Korean Heart Study

BackgroundAlthough reproductive and hormonal factors – such as early menarche and late menopause – have been reported as independent risk factors for cancer, few studies have examined these factors in East Asian populations.MethodsWe performed a large prospective cohort study of 66,466 women. Ovarian hormone exposure was defined as length of time between menarche and menopause. Incidence rates for breast, ovarian, endometrial and cervical cancers were examined separately in relation to reproductive lifespan defined as age at menopause minus age at menarche. Multivariable adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated using the Cox proportional hazards model.ResultsWomen with early menarche were at increased risk for developing breast cancer (HR, 1.57, 95% CI, 1.17–2.10) for age at menarche ≤12 years compared to women with age at menarche ≥17 years. Women with late age at menopause (≥52 years) had increased risks for cancers of the breast (HR, 1.59, 95%CI, 1.11–2.28) and ovary (HR, 3.22, 95% CI, 1.09–9.55) compared to women with early menopause (≤45 years of age). Women with longer duration of ovarian hormone exposure (≥40 years) were at increased risk for developing breast cancer (HR, 2.23, 95% CI, 1.35–3.68) as well as endometrial cancer (p for trend, 0.0209).ConclusionsWe showed that longer reproductive spans are associated with an increased risk of breast and endometrial cancer in Korean women.     

Risk factors for breast cancer in the breast cancer risk model study of Guam and Saipan

BackgroundChamorro Pacific Islanders in the Mariana Islands have breast cancer incidence rates similar to, but mortality rates higher than, those of U.S. women. As breast cancer risk factors of women of the Mariana Islands may be unique because of ethnic and cultural differences, we studied established and suspected risk factors for breast cancer in this unstudied population.MethodsFrom 2010–2013, we conducted retrospective case-control study of female breast cancer (104 cases and 185 controls) among women in the Mariana Islands. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each of various lifestyle-related factors from logistic regression of breast cancer, in all women and in pre- and postmenopausal women separately. Tests for interaction of risk factors with ethnicity were based on the Wald statistics for cross-product terms.ResultsOf the medical and reproductive factors considered — age at menarche, breastfeeding, number of live births, age at first live birth, hormone use, and menopause — only age at first live birth was confirmed. Age at first live birth, among parous women, was higher among cases (mean 24.9 years) than controls (mean 23.2 years); with increased breast cancer risk (OR = 2.53; 95% CI, 1.04–6.19 for age ≥ 30y compared to <20y, P for trend = 0.01). Of the lifestyle factors —body mass index, waist circumference, physical activity, alcohol and betel-nut intake, and education — only waist circumference (OR = 1.65; 95% CI 0.87–3.14 for the highest tertile group compared to the lowest, P for trend = 0.04) was significantly associated with breast cancer risk and only in Filipino women. The association with many other established risk factors, such as BMI, hormone use and physical activity, were in the expected direction but were not significant. Associations for family history of breast cancer and alcohol intake were not evidentConclusionsThe results provide a basis for cancer prevention guidance for women in the Mariana Islands.     

The life histories of American stepfathers in evolutionary perspective

This paper presents an analysis of the characteristics of men who become stepfathers, and their subsequent fertility patterns and lifetime reproductive success. Because women who already have children are ranked lower in the marriage market than women without children, men who marry women with children (e.g., stepfathers) are likely to have lower rankings in the marriage market as well. Using retrospective fertility and marital histories from the Panel Study of Income Dynamics (PSID), I show that men who become stepfathers have lower levels of education, less income, and are more likely to have been divorced before and to already have children, all characteristics that lower their rankings in the marriage market. Men with one or two stepchildren are just as likely to have children within a marriage as non-stepfathers, although men with three stepchildren show decreased fertility. Among men age 45 and older, stepfathers have lower lifetime fertility than non-stepfathers, although the difference disappears when men’s age at first marriage is controlled for. Additionally, stepfathers have significantly higher fertility than men who never marry. The results suggest that some men become stepfathers to procure mates and fertility benefits that they would otherwise have been unlikely to obtain; for these men, raising other men’s children serves as a form of mating effort. Preliminary versions of this paper were presented at the Evolution and Human Adaptation Program at the University of Michigan, and the Human Behavior and Evolution Society’s annual meeting at Amherst. Kermyt G. Anderson received his Ph.D. in anthropology from the University of New Mexico in 1999. He is currently a Mellon Postdoctoral Research Fellow at the Population Studies Center of the Institute for Social Research at the University of Michigan. His current research examines the relationship between family structure, parental investment, and children’s educational and employment outcomes in South Africa.     

Parity and breast cancer: evidence of a dual effect.

Epidemiological studies have shown that early first pregnancy reduces the risk of developing breast cancer, which indicates that initiation of the disease occurs at an early age. Thus the subclinical lesion of breast cancer might already be present in the breast before childbearing begins and the growth of any such focus might be modified by the endocrine changes of pregnancy. To test this hypothesis the relation between parity and age at presentation was studied in 341 unselected patients with breast cancer presenting to a single clinic. The mean age at presentation was 5.2 years lower in parous than nulliparous women (p < 0.001) and fell with increasing parity. It is concluded that reproductive history influences not only the risk of breast cancer but also the latent interval of a proportion of breast carcinomas.     

An energetics-based approach to understanding the menstrual cycle and menopause

To explain the menstrual cycle and menopause, human biologists during the past several decades have developed new models of the evolutionary origins and maintenance of female reproductive patterns that address both ultimate and proximate causation. Hypotheses proposed for these processes generally offer explanations for menstruation or for menopause, but not for both; ultimately, these explanations must be integrated. Reviewing current explanations, this paper offers an energetics-based evolutionary rationale compatible with past adaptations of Homo sapiens and with ecological patterns in small-scale, preindustrial social systems in which food resources vary and sometimes are scarce. This paper is an expansion of a poster paper presented at the 2002 Human Biology Association meetings in Buffalo, New York. Roberta L. Hall is professor of anthropology at Oregon State University. Her main interest is in evolutionary aspects of human biological variation. Current research involves body composition relationships with resting metabolic rate in males and females and climatic adaptions of nasal morphology. She also enjoys working with the Coquille Indian Tribe of southern Oregon on research concerning their prehistory and is studying ramifications of the coastal hypothesis of North American settlement.     

Nonmetric tooth crown traits in a Sri Lankan aboriginal Vedda population

This study was conducted to determine the frequencies of non-metric tooth crown traits of Vedda of Sri Lanka and to investigate the affinities of these morphological variations with those of other world populations.Fifty dental plaster casts were observed. The Arizona State University dental anthropology system was adopted for classification of the 16 traits observed. We used 13 traits to compare the Vedda and other world populations. Using the frequencies of 13 traits, Smith Mean Measure of Divergence was calculated to determine inter-population distances. Affinities among the Vedda and other world populations were expressed in two dimensions of the principal coordinate analysis.Cusp number in mandibular second molar and hypocone absence in maxillary second molar had the highest frequency at 95.9% and 93.8%, respectively. Shovelling, double shovelling in the maxillary central incisor and deflecting wrinkle in the mandibular first molar had the lowest frequency at 0%. The principal coordinate analysis showed that Sino American and Western Eurasian populations were separated in negative and positive directions in the first principal coordinate axis. Vedda located with the Western Eurasian population groups. Sahul and Sunda Pacific populations located in the intermediate position between Sino American and Western Eurasian populations.The dental phenotype of Vedda has close affinities with those of early south Asian populations. They are far different from Sino American and Sunda pacific populations. Vedda shows closer affinities to Sahul Pacific and South African (Bantu) populations.     

Girl helpers and time allocation of nursing women among the Toba of Argentina

In this paper we outline the activities of young girls in a Toba community of northern Argentina and examine the effect of girl helpers on time allocation of nursing women. Activity budgets were obtained for 41 girls aged 3 to 15 using spot observations. Girls spent substantial portions of observations engaged in helping behaviors. Individual values varied with age, anthropometric characteristics, and birth order. Activity budgets of 21 nursing women were obtained through focal observation sessions. Women living in households with girls aged 7 to 15 allocated 17% less time to domestic work and 9% more time to socializing during afternoon observation sessions. For nursing women in this community, direct childcare (provided by the infant’s own mother) seemed to be a priority. Living with a girl helper did not have any measurable effect on the frequency or duration of nursing, or on the time that women spent caring for their infants. Based on these findings, hypotheses are outlined for future work on the effect of girl helpers on women’s fertility. Research for this project was funded by the Nestlé Foundation, the Harvard Anthropology Goelet Fund, and the Harvard College Research Program. Eduardo Fernandez-Duque commented on an early draft of this paper. Riley Bove (A.B., Harvard, 1998) is a research associate in the Department of Anthropology at Harvard University with research interests in intergenerational female networks and polygyny as a social mediator of women’s health (esp. urban, African). Claudia Valeggia (Ph.D., U.C. Davis, 1996) is a postdoctoral fellow in the Department of Anthropology at Harvard University with research interests in reproductive ecology and ethnopediatry. Peter Ellison (Ph.D., Harvard, 1983) is a professor of anthropology and director of the Reproductive Ecology Laboratory at Harvard University. He is the author of On Fertile Ground: Ecology, Evolution and Human Reproduction (Harvard University Press, 2001).     

Escalating burden of breast cancer in southern Thailand: Analysis of 1990–2010 incidence and prediction of future trends

BackgroundThailand is undergoing an epidemiologic transition, with decreasing incidence of infectious diseases and increasing rates of chronic conditions, including cancer. Breast cancer has the highest incidence rates among females both in the southern region Thailand and throughout Thailand. However, there is a lack of research on the epidemiology of this and other cancers.MethodsHere we use cancer incidence data from the Songkhla Cancer Registry to characterize and analyze the incidence of breast cancer in Southern Thailand. We use joinpoint analysis, age-period-cohort models and nordpred analysis to investigate the incidence of breast cancer in Southern Thailand from 1990 to 2010 and project future trends from 2010 to 2029.ResultsWe found that age-adjusted breast cancer incidence rates in Southern Thailand increased by almost 300% from 1990 to 2010 going from 10.0 to 27.8 cases per 100,000 person-years. Both period and cohort effects played a role in shaping the increase in incidence. Three distinct incidence projection methods consistently suggested that incidence rates will continue to increase in the future with incidence for women age 50 and above increasing at a higher rate than for women below 50.ConclusionsTo date, this is the first study to examine Thai breast cancer incidence from a regional registry. This study provides a basis for future planning strategies in breast cancer prevention and to guide hypotheses for population-based epidemiologic research in Thailand.     

河北阳原姜家梁新石器时代人类牙齿形态特征的观察与研究

本文应用牙齿人类学的研究方法,对出自河北阳原姜家梁遗址的新石器时代居民的牙齿形态特征进行了研究。采用“亚利桑那州立大学牙齿人类学系统”进行牙齿形态观察,应用“平均差异度”(MMD)距离公式计算出姜家梁组与其他各对比组的MMD距离系数以估计群体间的相似程度,并根据MMD矩阵对18组人群进行聚类分析和因子分析。本文研究结果表明,姜家梁居民的牙齿形态特征属于中国型牙(Sinodonty),但自身又具有某些独特的特征,如铲形上颌中央门齿和单根上颌第一前臼齿等特征的出现率很高。综合来看,姜家梁组在铲形上颌中央门齿、双铲形上颌中央门齿、单根上颌第一前臼齿和第一臼齿转向皱纹这4项性状上具有很高的出现率;上颌第一臼齿釉质延伸、上颌第三臼齿退化、三根下颌第一臼齿和下颌第二臼齿四尖这四项性状出现率处于中等水平。与同时代的下王岗组和庙子沟组比较而言,姜家梁组与庙子沟组的关系更为密切,有研究表明姜家梁组居民与庙子沟组居民具有较为相近的头骨形态特征,本文研究结果表明两者具有较为接近的牙齿形态特征,这说明在体质特征上相近的人群在头骨形态特征和牙齿形态特征方面的表现可能较为一致,但只通过这两个对比组的比较结果而下此结论还为时过早,尚有待于积累更多的同类型族群的相关牙齿人类学资料验证之。