The Control of Precancerous Conditions of the Colon and Rectum

The early diagnosis and treatment of precancerous lesions is an important means of control of intestinal cancer. The precancerous tendency is relatively slight with solitary colo-rectal polyps, ulcerative colitis and bilharzial infestation, but it is exceptionally severe in familial colonic polyposis.For more than 30 years, research into the inheritance and treatment of familial polyposis has been continued at St. Mark''s Hospital, London, England, and more than 90 families have been investigated and family pedigrees prepared. These now include 1050 “members”, of whom 343 have had either polyposis or intestinal cancer, or both, the number with cancer being 243. One hundred and one of these 343 patients have been operated on at St. Mark''s, 61 undergoing colectomy and ileorectal anastomosis.Cancer control is achieved by keeping under supervision all members of a family who have already developed polyposis or who may do so later.     

Sperm Recovery and IVF after Testicular Sperm Extraction (TESE): Effect of Male Diagnosis and Use of Off-Site Surgical Centers on Sperm Recovery and IVF

Objective

Determine whether testicular sperm extractions and pregnancy outcomes are influenced by male and female infertility diagnoses, location of surgical center and time to cryopreservation.

Patients

One hundred and thirty men undergoing testicular sperm extraction and 76 couples undergoing 123 in vitro fertilization cycles with testicular sperm.

Outcome Measures

Successful sperm recovery defined as 1–2 sperm/0.5 mL by diagnosis including obstructive azoospermia (n = 60), non-obstructive azoospermia (n = 39), cancer (n = 14), paralysis (n = 7) and other (n = 10). Obstructive azoospermia was analyzed as congenital absence of the vas deferens (n = 22), vasectomy or failed vasectomy reversal (n = 37) and “other”(n = 1). Sperm recovery was also evaluated by surgical site including infertility clinic (n = 54), hospital operating room (n = 67) and physician’s office (n = 11). Treatment cycles were evaluated for number of oocytes, fertilization, embryo quality, implantation rate and clinical/ongoing pregnancies as related to male diagnosis, female diagnosis, and use of fresh or cryopreserved testicular sperm.

Results

Testicular sperm recovery from azoospermic males with all diagnoses was high (70 to 100%) except non-obstructive azoospermia (31%) and was not influenced by distance from surgical center to laboratory. Following in vitro fertilization, rate of fertilization was significantly lower with non-obstructive azoospermia (43%, p = <0.0001) compared to other male diagnoses (66%, p = <0.0001, 59% p = 0.015). No differences were noted in clinical pregnancy rate by male diagnosis; however, the delivery rate per cycle was significantly higher with obstructive azoospermia (38% p = 0.0371) compared to diagnoses of cancer, paralysis or other (16.7%). Women diagnosed with diminished ovarian reserve had a reduced clinical pregnancy rate (7.4% p = 0.007) compared to those with other diagnoses (44%).

Conclusion

Testicular sperm extraction is a safe and effective option regardless of the etiology of the azoospermia. The type of surgical center and/or its distance from the laboratory was not related to success. Men with non-obstructive azoospermia have a lower chance of successful sperm retrieval and fertilization.     

Immunogenicity of the carcinoembryonic antigen derived peptide 694 in HLA-A2 healthy donors and colorectal carcinoma patients

Carcinoembryonic antigen (CEACAM5) is commonly overexpressed in human colon cancer. Several antigenic peptides recognized by cytolytic CD8+ T-cells have been identified and used in colon cancer phase-I vaccination clinical trials. The HLA-A*0201-binding CEA_694–702 peptide was recently isolated from acid eluted MHC-I associated peptides from a human colon tumor cell line. However, the immunogenicity of this peptide in humans remains unknown. We found that the peptide CEA_694–702 binds weakly to HLA-A*0201 molecules and is ineffective at inducing specific CD8+ T-cell responses in healthy donors. Immunogenic-altered peptide ligands with increased affinity for HLA-A*0201 were identified. Importantly, the elicited cytolytic T lymphocyte (CTL) lines and clones cross-reacted with the wild-type CEA_694–702 peptide. Tumor cells expressing CEA were recognized in a peptide and HLA-A*0201 restricted fashion, but high-CEA expression levels appear to be required for CTL recognition. Finally, CEA-specific T-cell precursors could be readily expanded by in vitro stimulation of peripheral blood mononuclear cell (PBMC) from colon cancer patients with altered CEA peptide. However, the CEA-specific CD8+ T-cell clones derived from cancer patients revealed low-functional avidity and impaired tumor-cell recognition. Together, using T-cells to demonstrate the processing and presentation of the peptide CEA694-702, we were able to corroborate its presentation by tumor cells. However, the low avidity of the specific CTLs generated from cancer patients as well as the high-antigen expression levels required for CTL recognition pose serious concerns for the use of CEA694-702 in cancer immunotherapy.     

Radioimmunoassay of CSF for encephalitogenic basic protein: a diagnostic test for MS?

Competitive inhibition of binding between radioiodine-labelled encephalitogenic basic protein from human myelin (¹²⁵I-HEProt) and normal human alpha-2 macroglobulin and between ¹²⁵I-HEProt and rabbit antiHEProt serum was used to study concentrated cerebrospinal fluid (CSF) under “blind” control for cross-reactivity with HEProt. Samples of CSF from patients meeting the standard criteria for definite MS and possible MS, and from patients with optic neuritis and “other” diagnoses were studied. CSF from patients in all four groups was shown to have an inhibitor cross-reactive with HEProt when studied by the ¹²⁵I-HEProt/alpha-2 macroglobulin test, but the amount was significantly greater in the definite MS group than in the “other” group. Results of the two tests on CSF from MS patients correlated, suggesting that the tests were identifying the same inhibitor. It was concluded that CSF contains an inhibitor similar to HEProt and that the amount present in CSF could be a useful diagnostic marker of MS.     

Thyroid Nodules and Thyroid Cancer

A review of clinical and laboratory features of thyroid cancer, designed to help in a more precise selection of patients for operation, showed that factors contributing to a high index of suspicion of cancer include previous exposure to low doses of radiation, the presence of a firm, solitary thyroid nodule clearly different from the rest of the gland, a young patient, nodules that are “cold” on scan with radioiodine, and nodules that fail to regress after an adequate trial of thyroxine therapy. Factors contributing to a low index of suspicion of thyroid cancer include soft or cystic lesions, multinodular goiters, nodules that are “hot” on ¹³¹ I scan, and those that regress during thyroxine treatment.When these factors are used to select patients for surgical operation, about 30 percent are found to have thyroid cancer.Until more precise methods for preoperative diagnosis are established, it is suggested that this type of clinical selection may be very helpful in the management of patients with thyroid nodules or nontoxic goiter.     

Patients' & Healthcare Professionals' Values Regarding True- & False-Positive Diagnosis when Colorectal Cancer Screening by CT Colonography: Discrete Choice Experiment

Purpose

To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC) for colorectal cancer screening.

Materials and Methods

Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between “standard” CTC and “enhanced” CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses.

Results

Data from 122 participants were analysed. There were 30 (25%) non-traders for the cancer scenario and 20 (16%) for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to >85) drop in specificity, equating to 2250 (IQR 1250 to >4250) additional false-positives per additional true-positive cancer, at 0.2% prevalence. For polyps, the figure was 15% (IQR 7.5 to 55), equating to 6 (IQR 3 to 22) additional false-positives per additional true-positive polyp, at 25% prevalence. Tipping points were significantly higher for patients than professionals for both cancer (85 vs 25, p<0.001) and polyps (55 vs 15, p<0.001). Patients were willing to pay significantly more for increased sensitivity for cancer (p = 0.021).

Conclusion

When screening for colorectal cancer, patients and professionals believe gains in true-positive diagnoses are worth much more than the negative consequences of a corresponding rise in false-positives. Evaluation of screening tests should account for this.     

OVX1 and CEA in patients with colon carcinoma, colon polyps and benign colon disorders

The OVX1 tumor marker promises to complement CA125 for detection of early stage ovarian carcinoma. OVX1 has also been shown to be elevated in colon cancer patients. This study is designed to assess serum OVX1 levels in patients with specific stages of colon cancer, colon polyps or other GI disorders. Serum OVX1 and CEA were measured by radioimmunoassay or enzyme immunoassay for 206 patients at the time of colonoscopy or staging for colon carcinoma. In patients with stage I, II, III, or IV colon carcinoma, serum OVX1 was positive in 37%, 48%, 74% and 63%, respectively. Fifty-three percent of patients with colon polyps had elevated OVX1 levels, while OVX1 levels were positive in only 7% of healthy controls. If both OVX1 and CEA were considered, at least one of these markers was elevated in 36%, 60%, 79% or 89% of patients with stage I, II, III or IV colon carcinoma, respectively. The majority of patients with inflammatory bowel disease or diverticulosis also had elevated OVX1 levels. Both markers were positive in 27% of patients with colon carcinoma, and not in any patients with a normal colonoscopy or with a diagnosis of diverticulosis or hemorrhoids. In conclusion, serum OVX1 improves the sensitivity of CEA for detecting colon polyps and colon cancer; however, the use of OVX1 in this setting is hindered by its elevation in non-malignant colonic processes.     

MALIGNANT LYMPHOMA OF THE COLON AND RECTUM—Roentgen Diagnosis

The filling defects of a particular lymphosarcoma of the colon or rectum may present an appearance identical to that of a carcinoma in the same location. In general, lymphosarcomas tend to be longer, more distensible, less sharply demarcated, more frequently polypoid, and to feel larger as palpable masses. The filling defects are infrequently of the annular “napkin ring” appearance, and occasionally the involved segment is dilated.     

Genetic Composition of Laboratory Stocks of the Self-Fertilizing Fish Kryptolebias marmoratus: A Valuable Resource for Experimental Research

The hermaphroditic Mangrove Killifish, Kryptolebias marmoratus, is the world''s only vertebrate that routinely self-fertilizes. As such, highly inbred and presumably isogenic “clonal” lineages of this androdioecious species have long been maintained in several laboratories and used in a wide variety of experiments that require genetically uniform vertebrate specimens. Here we conduct a genetic inventory of essentially all laboratory stocks of the Mangrove Killifish held worldwide. At 32 microsatellite loci, these stocks proved to show extensive interline differentiation as well as some intraline variation, much of which can be attributed to post-origin de novo mutations and/or to the segregation of polymorphisms from wild progenitors. Our genetic findings also document that many of the surveyed laboratory strains are not what they have been labeled, apparently due to the rather frequent mishandling or unintended mixing of various laboratory stocks over the years. Our genetic inventory should help to clarify much of this confusion about the clonal identities and genetic relationships of laboratory lines, and thereby help to rejuvenate interest in K. marmoratus as a reliable vertebrate model for experimental research that requires or can capitalize upon “clonal” replicate specimens.     

Ocular Manifestations of Hemoglobin S-C Disease

Three patients with hemoglobin S-C disease, all with ocular lesions, were studied and contrasted with four other patients who had predominantly either hemoglobin S or C but no ocular lesions. Attention is drawn to the diagnostic value of hemoglobin electrophoresis in such cases. With this technique a diagnosis of hemoglobin S-C disease was made in a patient previously thought to the “Eales'' disease”; one sister was found to have asymptomatic hemoglobin S-C disease and unsuspected early ocular lesions. The number of persons in Canada with hemoglobinopathies is increasing. Awareness of an association between abnormal hemoglobins and ocular disease may lead to the recognition of an unsuspected blood disorder or of an unsuspected retinopathy.     

Overall Survival of Stage III Colon Cancer with Only One Lymph Node Metastasis Is Independently Predicted by Preoperative Carcinoembryonic Antigen Level and Lymph Node Sampling Status

Background

This study identified predictors of favorable overall survival (OS) for stage III colon cancer patients who had only one lymph node (LN) metastasis (N1a).

Methods

Variables, including preoperative carcinoembryonic antigen (CEA) level, LN sampling status, and the choices of postoperative adjuvant chemotherapy, were recorded. Prognostic significance was determined using the log-rank test and multivariate Cox regression analysis.

Results

The median 42-month follow-up period included 363 eligible patients. Among them, 230 (63.3%) received only 5-flurouracil (5-FU) adjuvant chemotherapy; 76 (20.9%) underwent oxaliplatin-based regimens; and 57 (15.7%) chose surgery alone. The 5-year survival rate of these evaluated patients was 75%, 63%, and 77%, respectively (P = 0.823). Multivariate analysis revealed that normal preoperative CEA level (≦5 ng/mL) and adequate LN sampling (LN ≧ 12) were significant predictors for higher 5-year OS (P < 0.001; P = 0.007, respectively). However, the use of postoperative adjuvant chemotherapy in these N1a colon cancer patients did not significantly affect their 5-year OS.

Conclusions

A preoperative CEA level of less than or equal to 5 ng/mL, and curative surgery with an adequate lymphadenectomy determined a favorable OS outcome in stage III colon cancer with only one LN metastasis.     

Impact of Diabetes on Oncologic Outcome of Colorectal Cancer Patients: Colon vs. Rectal Cancer

Background

To evaluate the impact of diabetes on outcomes in colorectal cancer patients and to examine whether this association varies by the location of tumor (colon vs. rectum).

Patients and methods

This study includes 4,131 stage I-III colorectal cancer patients, treated between 1995 and 2007 (12.5% diabetic, 53% colon, 47% rectal) in South Korea. Cox proportional hazards modeling was used to determine the prognostic influence of DM on survival endpoints.

Results

Colorectal cancer patients with DM had significantly worse disease-free survival (DFS) [hazard ratio (HR) 1.17, 95% confidence interval (CI): 1.00–1.37] compared with patients without DM. When considering colon and rectal cancer independently, DM was significantly associated with worse overall survival (OS) (HR: 1.46, 95% CI: 1.11–1.92), DFS (HR: 1.45, 95% CI: 1.15–1.84) and recurrence-free survival (RFS) (HR: 1.32, 95% CI: 0.98–1.76) in colon cancer patients. No association for OS, DFS or RFS was observed in rectal cancer patients. There was significant interaction of location of tumor (colon vs. rectal cancer) with DM on OS (P = 0.009) and DFS (P = 0.007).

Conclusions

This study suggests that DM negatively impacts survival outcomes of patients with colon cancer but not rectal cancer.     

Serum amino acid profiles and their alterations in colorectal cancer

Mass spectrometry-based serum metabolic profiling is a promising tool to analyse complex cancer associated metabolic alterations, which may broaden our pathophysiological understanding of the disease and may function as a source of new cancer-associated biomarkers. Highly standardized serum samples of patients suffering from colon cancer (n?=?59) and controls (n?=?58) were collected at the University Hospital Leipzig. We based our investigations on amino acid screening profiles using electrospray tandem-mass spectrometry. Metabolic profiles were evaluated using the Analyst 1.4.2 software. General, comparative and equivalence statistics were performed by R 2.12.2. 11 out of 26 serum amino acid concentrations were significantly different between colorectal cancer patients and healthy controls. We found a model including CEA, glycine, and tyrosine as best discriminating and superior to CEA alone with an AUROC of 0.878 (95% CI 0.815-0.941). Our serum metabolic profiling in colon cancer revealed multiple significant disease-associated alterations in the amino acid profile with promising diagnostic power. Further large-scale studies are necessary to elucidate the potential of our model also to discriminate between cancer and potential differential diagnoses. In conclusion, serum glycine and tyrosine in combination with CEA are superior to CEA for the discrimination between colorectal cancer patients and controls.     

Prognostic Significance of Molecular Analysis of Peritoneal Fluid for Patients with Gastric Cancer: A Meta-Analysis

Background

Accurately distinguishing serosal invasion in patients with gastric cancer (GC) prior to surgery can be difficult. Molecular analysis of peritoneal fluid (MAPF) for free cancer cells with higher sensitivity than other methods; however, its prognostic value for GC remains controversial, precluding its application in clinical practice.

Methods

PubMed, EMBASE and other databases were systematically searched. Thirty-one studies were eligible for the meta-analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled for overall survival (OS), disease-free survival (DFS) and peritoneal recurrence-free survival (PRF).

Results

The current meta-analysis focused on patients with GC and negative cytological diagnoses. The results showed that positive MAPF status (MAPF⁺) led to poorer prognoses for OS (HR 2.59, 95% CI 1.99–3.37), DFS (HR 4.92, 95% CI 3.28–7.37) and PRF (HR 2.81, 95% CI 2.12–3.72) compared with negative MAPF status (MAPF^-). Moreover, among the patients with GC who received curative treatment, the MAPF⁺ patients had poorer prognoses for OS (HR 3.27, 95% CI 2.49–4.29), DFS (HR 3.90, 95% CI 2.74–5.57) and PRF (HR 5.45, 95% CI 3.70–8.03). A meta-analysis of multivariate-adjusted HRs demonstrated that MAPF⁺ status was an independent prognostic factor for patients with GC who underwent curative treatment (OS: HR 2.19, 95% CI 1.47–3.28; PRF: HR 3.44, 95% CI 2.01–5.87). Using the identical target genes (CEA, CEA/CK20) as molecular markers, the patients with GC who were MAPF⁺ had significantly worse prognoses for OS (CEA: HR 3.03, 95% CI 2.29–4.01; CEA/CK20: HR 4.24, 95% CI 2.42–7.40), DFS (CEA: HR 3.99, 95% CI 2.24–7.12; CEA/CK20: HR 4.31, 95% CI 1.49–2.48) and PRF (CEA: HR 4.45, 95% CI 2.72–7.31; CEA/CK20: HR 6.46, 95% CI 3.62–11.55) than the patients who were MAPF^-.

Conclusion/Significance

The above results demonstrate that MAPF could be a prognostic indicator for patients with GC who have a negative cytological diagnosis and/or are receiving curative treatment. MAPF could provide clinicians with additional prognostic information that could aid in developing individualized treatment plans prior to surgery. The widely used target genes CEA, CEA/CK20 were confirmed to be valuable MAPF markers for predicting the prognosis of GC.     

Gatekeepers or Intermediaries? The Role of Clinicians in Commercial Genomic Testing

Background

Many commentators on “direct-to-consumer” genetic risk information have raised concerns that giving results to individuals with insufficient knowledge and training in genomics may harm consumers, the health care system, and society. In response, several commercial laboratories offering genomic risk profiling have shifted to more traditional “direct-to-provider” (DTP) marketing strategies, repositioning clinicians as the intended recipients of advertising of laboratory services and as gatekeepers to personal genomic information. Increasing popularity of next generation sequencing puts a premium on ensuring that those who are charged with interpreting, translating, communicating and managing commercial genomic risk information are appropriately equipped for the job. To shed light on their gatekeeping role, we conducted a study to assess how and why early clinical users of genomic risk assessment incorporate these tools in their clinical practices and how they interpret genomic information for their patients.

Methods and Findings

We conducted qualitative in-depth interviews with 18 clinicians providing genomic risk assessment services to their patients in partnership with DNA Direct and Navigenics. Our findings suggest that clinicians learned most of what they knew about genomics directly from the commercial laboratories. Clinicians rely on the expertise of the commercial laboratories without the ability to critically evaluate the knowledge or assess risks.

Conclusions

DTP service delivery model cannot guarantee that providers will have adequate expertise or sound clinical judgment. Even if clinicians want greater genomic knowledge, the current market structure is unlikely to build the independent substantive expertise of clinicians, but rather promote its continued outsourcing. Because commercial laboratories have the most “skin in the game” financially, genetics professionals and policymakers should scrutinize the scientific validity and clinical soundness of the process by which these laboratories interpret their findings to assess whether self-interested commercial sources are the most appropriate entities for gate-keeping genomic interpretation.     

CYTOLOGIC DETECTION OF CERVICAL CANCER—Four Years' Experience with Routine Smear Examination in Private Practice

Simplified Papanicolaou smear techniques appear to be adaptable to private clinical practice when experienced cytodetection laboratory facilities are available. A private physician''s office seems potentially an efficient, economical and practical place for detection of cervical cancer by use of the smear technique as a routine part of examination of patients.In a series here reported upon, examination of 11,207 cervical smears taken at the first examination of patients of all ages led to diagnosis of unsuspected malignant disease in 80 cases—in all instances at a stage when it should be easily curable. Cancer was not detected in examination of 6,060 smears taken later from women who had had a “negative” smear at the time of first examination, which seems to indicate that the first screening was reasonably accurate.In a few cases, early cancer was detected when smears were reported as “atypical” or “suspicious.” Such reports demand as careful follow-up as do “positive” reports.There are dangers and limitations in wide-spread clinical application of screening by this method. Care must be observed in the development of programs for its use lest the potential benefits in early detection be outweighed by the dangers from misuse.     

Surveillance of acute respiratory virus infections in general practice

The ordinary postal system provides a simple method for the transportation of specimens for virus isolation to the laboratory. This was used to carry out an epidemiological survey, in general practice, of respiratory viruses in patients with acute respiratory disease. Three distinct outbreaks of myxovirus infections were recognized and most other types of respiratory viruses were isolated sporadically. After the initial “pilot” phase of the study an isolation rate of 24% was obtained over the months from October 1968 to June 1969 (20% isolations from adults'' specimens and 29% from those of children).     

Molecular Diagnostics of Fine Needle Aspiration for the Presurgical Screening of Thyroid Nodules

“The incidence of thyroid cancer, the most common endocrine malignancy, is rising. The two most common types of thyroid cancer are papillary and follicular” thyroid carcinomas. “Fine-needle aspiration (FNA) of thyroid nodules” can permit to detect many genetic mutations and other molecular alterations, including RAS and BRAF point mutations, PAX8/peroxisome proliferator-activated receptor (PPAR)γ and “RET/PTC rearrangements, occurring in thyroid papillary and follicular carcinomas” (more than 70% of cases), which can be used successfully to improve the diagnosis “and the management of patients with thyroid nodules”. The most extensive experience has been accumulated with “the diagnostic use of BRAF mutation”, which is highly specific for malignancy. “Testing FNA samples for a panel of mutations” that typically includes RAS, BRAF, PAX8/PPARγ and RET/PTC could permit to achieve the biggest diagnostic impact. “The accuracy of cancer diagnosis in thyroid nodules could be improved significantly using these and other emerging molecular markers”.     

Microbial Contamination on Disposable Hypodermic Syringes Prior to Sterilization by Ionizing Radiation

A large number of syringes were taken from the production lines of three independent manufacturers; the numbers and types of microorganisms contaminating these randomly sampled syringes were assessed in the laboratories maintained by each of these manufacturers for routine sterility testing, according to a standard protocol devised by the Research Committee of the UK Panel on Gamma and Electron Irradiation, which coordinated the investigation and analyzed the results. Items produced by a manufacturer were assessed for microbiological contamination both in their own laboratories and in the laboratories of the other manufacturers. The level of “false-positive” results was determined independently for each laboratory by the testing of “known sterile” items which had been subjected to the radiation-sterilization process. Both the percentage of syringes initially sterile and the average number of organisms per contaminated syringe differed among the three manufacturers. When corrected for interlaboratory differences, the number of syringes initially sterile ranged from 16 to 48%, and the mean number of organisms per contaminated syringe was 20 to 70. Of 964 syringes tested by all three laboratories, only one contained over 1,000 aerobic organisms (1,133). The most common organisms found were coagulase-negative, gram-positive cocci. Two manufacturers assessed contamination by anaerobic organisms; of 610 syringes, 1 contained 4,275 organisms and 3 more had 100 to 1,000 organisms, but 488 (80%) were uncontaminated by anaerobes. The results are discussed in the context of the choice of radiation dose necessary for the sterilization of medical products manufactured under controlled hygienic conditions.     

CEA levels in gastric juice in precancerous conditions and cancer

First described in 1965 as a specific antigen for cancer of the colon, CEA is now considered to be an antigen associated with many types of malignant neoplasia, although the CEA-Test's role in clinical routine has yet to be clearly defined. In the present study CEA levels in gastric juice were measured in subjects with gastric carcinoma (n = 25) and with benign gastric lesions (n = 171). CEA was significantly (p less than 0.05) higher in patients with gastric carcinoma (GC) than in subjects with benign gastric lesions, other than chronic atrophic gastritis (CAG) associated with intestinal metaplasia (IM). In this latter condition CEA levels were similar to those in patients with GC. These results suggest that the assay of CEA in gastric juice could be included in the diagnostic program for gastric cancer and its precursors with the aim of assessing its utility as risk indicator in the management of precancerous conditions and lesion.