Transition of cancer in populations in India

Background & objectivesAn assessment of transition of cancer in India during the past 30 years, according to changes in demographic and epidemiologic risk factors was undertaken.Materials & methodsCancer registry data (http://www.ncdirindia.org), (population coverage <10%), was compared with transition in life-expectancy and prevalence on smoking, alcohol and obesity. We fitted linear regression to the natural logarithm of the estimated incidence rates of various cancer registries in India.ResultsBurden of cancer in India increased from 0.6 million in 1991 to 1.4 million in 2015. Among males, common cancers are lung (12.0%), mouth (11.4%), prostate (7.0%), and tongue (7.0%) and among females, they are breast (21.0%), cervix-uteri (12.1%), ovary (6.9%), and lung (4.9%) in 2012. Increased life-expectancy and population growth as well as increased use of alcohol and increased prevalence of overweight/obesity reflected an increase in all cancers in both genders except a reduction in infection-related cancers such as cervix-uteri and tobacco-related cancers such as pharynx (excludes nasopharynx) and oesophagus.Interpretation & conclusionTransition in demographics and epidemiologic risk factors, reflected an increase in all cancers in both genders except a reduction in a few cancers. The increasing incidence of cancer and its associated factors demands a planned approach to reduce its burden. The burden assessment needs to be strengthened by increasing the population coverage of cancer registries. Continued effort for tobacco prevention and public health efforts for reducing obesity and alcohol consumption are needed to reduce the cancer burden.     

Raman exfoliative cytology for prognosis prediction in oral cancers: A proof of concept study

Oral cancer is associated with high rates of recurrence, attributable to field cancerization. Early detection of advanced field changes that can potentially progress to carcinoma can facilitate timely intervention and can lead to improved prognosis. Previous in vivo studies have successfully detected advanced field effects in oral cancers. Raman exfoliative cytology has previously shown to differentiate normal, oral pre‐cancer and cancers. The present study explores Raman‐exfoliative‐cytology‐based detection of field effects. Exfoliated cells were collected from tumor (n = 16) and contralateral‐normal appearing mucosa (n = 16) of oral cancer patients, and healthy tobacco habitués (n = 20). After spectral acquisition, specimens were Pap‐stained for cytological evaluation. Data analysis, by Principal Component Analysis and Principal Component‐Linear Discriminant Analysis, indicate several spectral‐misclassifications between contralateral normal and tumor, which were investigated and correlated with spectral, cytological and clinical outcomes. A qualitative analysis by grouping patients with number of misclassifications with tumor (Group 1: 0, Group 2: 1 and Group 3: >1) was explored. Group 3 with highest misclassifications showed spectral and cytological similarity to tumor group — one patient was a case of early inoperable residual disease, despite clear margins on histopathology. Thus, these misclassifications could be indicative of cancer field changes, and can prospectively help to identify patients susceptible to recurrences .     

Abundance and state of phosphorylation of the retinoblastoma susceptibility gene product in human colon cancer

In an effort to understand the possible role of Rb in cellular growth control, we have investigated the abundance and the state of phosphorylation of Rb protein (pRb) in normal and colon tumor cell lines as well as in matched colon tumors, adenomas and adjoining normal colonic mucosa. Resting normal human fibroblast cell lines were found to have only unphosphorylated pRb and phosphorylation of pRb occurred when the cells entered G1-S phase. In general, the colon tumor tissues had atleast 1.5–2.0 fold increase in the abundance of pRb and 1.5–2.5 fold increase in the percentage of its phosphorylation as compared to the corresponding normal colonic mucosa. Whereas, the adenomas had similar pRb level and its phosphorylation status as observed in the normal colonic mucosa. The actively growing tumor cell lines had approximately two fold higher total pRb than normal cell lines. Although, the percentage of phosphorylated form in growing tumor cell lines as well as normal cell lines were almost equal, it was still considerably higher than normal colonic mucosa. Moreover, DNA binding assay revealed reduced binding affinity of pRb from colon tumor cell line SW480 as compared to the normal cell line W138. These results suggest that the abundance of pRb and its phosphorylation level may have a role in the cellular growth control in human colonic epithelium.     

聚合酶链反应检测宫颈癌中HPV16E6／E7相关序列

本文报告了采用聚合酶链反应(即PCR技术)检测人宫颈癌中人乳头瘤病毒16型(HPV16)的E_6/E_7相关序列。在正链引物(SP)和反链引物(ASP)的诱导下,以二步温控法聚合酶链反应对34例人宫颈癌组织DNA进行检测,发现宫颈癌中HPV16E_6/E_7相关序列存在的阳性率达67.6％(23/34)。本研究结果提示:HPV16可能在宫颈癌的发生发展过程中起重要作用,采用PCR技术选择性地检测HPV16的转化基因(E_6、E_7)对深入探讨宫颈癌发生的机理、早期发现宫颈癌患者等有重要意义。     

循环肿瘤细胞在女性实体器官肿瘤中的研究进展

循环肿瘤细胞(circulating tumor cells,CTCs)指的是从实体的肿瘤或转移的病灶进入外周血液循环的恶性肿瘤细胞。自发现以来,随着其检验技术日趋成熟,循环肿瘤细胞(CTCs)日渐成为肿瘤学炙手可热的研究对象。因为它将通过外周血的检验来实现监测肿瘤的发生、发展、转移、复发等情况,相对于肿瘤实体活检,"液体活检"不仅让患者易于接受,更有利于医务工作者监测病情变化。本文综述了循环肿瘤细胞(CTCs)的检测方法并综述了循环肿瘤细胞在女性实体肿瘤--乳腺癌、卵巢癌、宫颈癌、子宫内膜癌中的研究进展。其中着重介绍了其在早期乳腺癌及复发转移性乳腺癌中的重大意义以及在评价治疗效果中的分子学特征。实践表明,循环肿瘤细胞(CTCs)与HE-4、CA125的联合应用在评估卵巢癌化疗敏感性中也具有重要的临床意义。     

The burden of rare cancer in Japan: Application of the RARECARE definition

BackgroundDespite the fact that rare cancer is a new target of cancer control in Japan, the incidence of rare cancers is unknown and there is no generally accepted definition of rare cancers in this country. With the aim of calculating incidences of rare cancers in Japan, we therefore adopted a definition and classification of rare cancers that had been published in the European Union (EU) in 2011.MethodsUsing incidence data between 1998 and 2007 submitted by 12 of population based cancer registries in Japan that met our quality criteria and drawing on the EU definition (incidence <6 per 100,000 per year), we estimated the incidences of 845 combinations of tumor sites and histological groups and thus identified the cancers that are rare in Japan.ResultsAfter identifying 193 combinations of tumor sites and histological groups that fit our criteria for rare cancers, we estimated their incidence to be about 75 per 100,000, which corresponds to about 94,800 new diagnoses in 2012 or approximately 15% of all cancer diagnoses. The categorization of rare and common cancers was almost the same in Japan as in EU.ConclusionsThe present study provides an indication of the size of the rare cancer burden in Japan and epidemiological information to explore this. We are expecting further discussion based on our results with stakeholders in order to construct a Japanese definition of rare cancers.     

A study on conventional IMRT and RapidArc treatment planning techniques for head and neck cancers

AimTo evaluate the performance of volumetric arc modulation with RapidArc against conventional IMRT for head and neck cancers.BackgroundRapidArc is a novel technique that has recently been made available for clinical use. Planning study was done for volumetric arc modulation with RapidArc against conventional IMRT for head and neck cancers.Materials and methodsTen patients with advanced tumors of the nasopharynx, oropharynx, and hypopharynx were selected for the planning comparison study. PTV was delineated for two different dose levels and planning was done by means of simultaneously integrated boost technique. A total dose of 70 Gy was delivered to the boost volume (PTV boost) and 57.7 Gy to the elective PTV (PTV elective) in 35 equal treatment fractions. PTV boost consisted of the gross tumor volume and lymph nodes containing visible macroscopic tumor or biopsy-proven positive lymph nodes, whereas the PTV elective consisted of elective nodal regions. Planning was done for IMRT using 9 fields and RapidArc with single arc, double arc. Beam was equally placed for IMRT plans. Single arc RapidArc plan utilizes full 360° gantry rotation and double arc consists of 2 co-planar arcs of 360° in clockwise and counter clockwise direction. Collimator was rotated from 35 to 45° to cover the entire tumor, which reduced the tongue and groove effect during gantry rotation. All plans were generated with 6 MV X-rays for CLINAC 2100 Linear Accelerator. Calculations were done in the Eclipse treatment planning system (version 8.6) using the AAA algorithm.ResultsDouble arc plans show superior dose homogeneity in PTV compared to a single arc and IMRT 9 field technique. Target coverage was almost similar in all the techniques. The sparing of spinal cord in terms of the maximum dose was better in the double arc technique by 4.5% when compared to the IMRT 9 field and single arc techniques. For healthy tissue, no significant changes were observed between the plans in terms of the mean dose and integral dose. But RapidArc plans showed a reduction in the volume of the healthy tissue irradiated at V_15 Gy (5.81% for single arc and 4.69% for double arc) and V_20 Gy (7.55% for single arc and 5.89% for double arc) dose levels when compared to the 9-Field IMRT technique. For brain stem, maximum dose was similar in all the techniques. The average MU (±SD) needed to deliver the dose of 200 cGy per fraction was 474 ± 80 MU and 447 ± 45 MU for double arc and single arc as against 948 ± 162 MU for the 9-Field IMRT plan. A considerable reduction in maximum dose to the mandible by 6.05% was observed with double arc plan. Double arc shows a reduction in the parotid mean dose when compared with single arc and IMRT plans.ConclusionRapidArc using double arc provided a significant sparing of OARs and healthy tissue without compromising target coverage compared to IMRT. The main disadvantage with IMRT observed was higher monitor units and longer treatment time.     

拉曼光谱技术在肿瘤检测中的应用

癌症是威胁人类健康和生命的严重疾病之一,早期诊断与及时治疗是提高癌症患者生存率的最有效途径。激光拉曼光谱技术作为一种非侵入性的检测技术,可以无损伤地提供丰富的分子结构特征和物质成分信息,从分子水平上反映癌变组织与正常组织之间的结构差异,从而可用于癌症的早期诊断。综述了激光拉曼光谱技术在皮肤癌、鼻咽癌、肺癌、胃癌、结肠癌、乳腺癌及前列腺癌诊断中的研究进展,并对拉曼光谱技术在癌症诊断中的发展方向和应用前景作了进一步的展望,为癌症的早期检测和诊断技术的应用研究提供参考依据。