Breast cancer, colorectal cancer, and esophageal cancer

This is the second of a six-part series on metastatic spread and natural history of 18 common tumors. Part one summarized symptom/problem anticipation, cancer metastasis, and the 18 tumors that each cause more than 6,000 deaths per year in the United States. Bladder and brain cancer were discussed, with information given on tumor types, metastatic spread and invasion, and common symptoms. Part two charts the natural histories of breast, colorectal, and esophageal cancers. Each of these cancers is presented separately, with information given on mortality rates, the most common tumor types, sites of metastases, common problems, and common oncologic emergencies. Sites of spread, resulting problems (including site-specific symptoms), and assessment parameters are presented as tables. Material is presented so that clinicians will be able to anticipate the spread of these cancers and thus identify problems early in their development so that the problems are more easily managed.     

Attributed risk to smoking for lung cancer,laryngeal cancer and esophageal cancer

OBJECTIVE: Lung, laryngeal and esophageal cancers have smoking as one of their main risk factors. The objective of this study was to evaluate the population attributed risk (PAR) of smoking for these forms of cancer. METHODS: The study was based in three case-control studies conducted in medium size cities in Brazil. Incident cases of lung cancer, laryngeal cancer and esophageal cancer seen at a hospital setting and diagnosed through biopsy were analyzed; controls were hospitalized patients with another diagnoses. Smoking was the exposure factor measured at three levels: non-smokers, former smokers and smokers, which were defined using a questionnaire applied by trained interviewers. For effect measure, odds ratio was used and the populational attributed risk for smoking was then calculated for a 95% CI. RESULTS: A total of 122 lung cancer cases and 244 controls, 50 cases of laryngeal cancer and 48 cases of esophageal cancer, and 96 controls for both of them were studied. The prevalence of smoking exposure was 34%, which is the overall prevalence of smoking in this city's adult population. Odds ratios (OR) for the PAR analysis were the adjusted OR for confounding variables from each study. Lung cancer PAR was 63% (95% IC, 0.58-0.68) for former smokers and 71% (95%IC, 0.65-0.77) for smokers. Larynx cancer PAR was 74% (95% IC, 0.70-0.78) and 86% (95%IC, 0.81-0.85) for former smokers and smokers, respectively. Esophageal cancer PAR was 54% (95%IC, 0.46-0.62) for smokers. CONCLUSION: Smoking is an avoidable risk factor and smoking cessation could be responsible for significant reductions in the incidence of these three forms of cancer.     

Beliefs about causes of cancer in cancer patients

Beliefs about causes of cancer were studied in 120 patients with late-stage cancer and compared with beliefs of non-cancer patients matched for age, sex, and hospitalization. Cancer patients consistently had less strong beliefs about causes of cancer than did the other groups, even when causes such as smoking and having pulmonary cancer were probably associated with the development of their disease. Although some correlates of beliefs were found in cancer patients' personal and social background, these were generally of minimal levels of statistical significance. Those who had been diagnosed longer believed cancer was more often inherited. The non-cancer patients' beliefs were similar to those found in a large survey of the general population. It is likely that cancer patients need to defend themselves against self-blame as a means of coping with a terminal illness.     

Cervical cancer in Bangladesh: community perceptions of cervical cancer and cervical cancer screening

We investigated the awareness of, and the attitude towards screening for, cervical cancer in Bangladesh. We performed a qualitative study using focus group discussions (FGD). The framework approach to qualitative analysis was used. The study was performed in the catchment areas of Addin Hospital, Jessore, Southern Bangladesh (peri-urban) and LAMB hospital, Parbatipur, North West Bangladesh (rural). A total of 220 men, women and adolescents participated in 28 FGDs. Awareness of cervical cancer was widespread. Knowledge about causes was often inadequate. The perceived consequences of cervical cancer were numerous and awareness of the need for cervical cancer treatment was present. Barriers to accessing care include: low priority for seeking help for symptoms, limited availability of health services and cost. Most women were unaware of the possibility of screening via speculum examination, which was considered acceptable to women (and men), as long as the examination was done by a female healthcare provider in an environment with sufficient privacy. In conclusion, adequate gynaecological services are not available or accessible for most women in rural and peri-urban Bangladesh. However, awareness of cervical cancer is widespread. Screening for cervical cancer in these communities is acceptable if done by a female healthcare provider under conditions with sufficient privacy.     

Reproductive cancer

The increasing life expectancy of our population will mean that by the year 2000 we may expect a large number of women to be in age groups at significant risk for malignancies of the female reproductive tract. It is very unlikely that we will soon understand the cause of cancer, and effective new therapies are not to be anticipated. Rather, improved survival and diminished morbidity must be obtained by insuring ready and equal access to state of the art treatment, for the patient and physician.     

Personalized cancer vaccines: Targeting the cancer mutanome

The development of next generation sequencing technologies has revolutionized our understanding of how specific genetic events contribute to cancer initiation and progression. Dramatic improvements in instrument design and efficiency, combined with significant cost reductions has permitted a systematic analysis of the mutational landscape in a variety of cancer types. At the same time, a detailed map of the cancer mutanome in individual cancers offers a unique opportunity to develop personalized cancer vaccine strategies targeting neoantigens. Recent studies in both preclinical models and human cancer patients demonstrate that neoantigens (1) are important targets following checkpoint inhibition therapy, (2) have been identified as the target of adoptive T cell therapies, and (3) can be successfully targeted with personalized vaccines. Taken together, these observations provide strong rationale for the clinical translation of personalized cancer vaccines.     

Nutrigenetics in cancer research--folate metabolism and colorectal cancer

The B vitamin folate is essential for one-carbon transfer reactions, including those related to the methylation of DNA or other substrates and nucleotide synthesis. Epidemiologic and experimental studies implicate low-folate intakes in elevated risk of colorectal neoplasia and suggest that biologic mechanisms underlying this relation include disturbances in DNA methylation patterns or adverse effects on DNA synthesis and repair. With the completion of the Human Genome Project, a vast amount of data on inherited genetic variability has become available. This genetic information can be used in studies of molecular epidemiology to provide information on multiple aspects of folate metabolism. First, studies linking polymorphisms in folate metabolism to an altered risk of cancer provide evidence for a causal link between this pathway and colorectal carcinogenesis. Second, studies on genetic characteristics can help clarify whether certain individuals may benefit from higher or lower intakes of folate or nutrients relevant to folate metabolism. Third, studies on genetic polymorphisms can generate hypotheses regarding possible biologic mechanisms that connect this pathway to carcinogenesis. Last, genetic variability in folate metabolism may predict survival after a cancer diagnosis, possibly via pharmacogenetic effects. To solve the puzzle of the folate-cancer relation, a transdisciplinary approach is needed that integrates knowledge from epidemiology, clinical studies, experimental nutrition, and mathematical modeling. This review illustrates knowledge that can be gained from molecular epidemiology in the context of nutrigenetics, and the questions that this approach can answer or raise.     

Second primary ovarian cancer among women with cancer

PURPOSE: Some studies suggest women with certain types of cancers are at increased risk for ovarian cancer. This study assessed the risk of second primary ovarian cancer among U.S. women who have cancer by anatomic site, age, race, and time since diagnosis of the first primary cancer.METHODS: We analyzed data from SEER cancer registries for women diagnosed with invasive cancer between 1973 and 1996. Person-years were accumulated from 2 months after initial cancer diagnosis to date of ovarian cancer diagnosis, death, loss to follow-up, or end of follow-up, December 31, 1996. The expected number of cases was obtained by multiplying 5-year age and calendar year interval specific ovarian cancer rates by the accumulated person-years at risk. We calculated the risk (observed [O]/expected numbers [E]) of second primary ovarian cancer by cancer site and age (<50 years, >/=50 years), race (all, white, black), and time since first cancer (0-4, 5-9, 10-14, 15-24 years). Statistical tests and 95% confidence intervals (CI) were based on the assumption of a Poisson distribution.RESULTS: A significant increased risk of ovarian cancer was found for women aged <50 years at time of diagnosis with melanoma (O/E = 3.5, 95% CI = 2.1-5.5) and cancer of the breast (O/E = 6.0, 95% CI = 4.9-7.2), cervix (O/E = 4.2, 95% CI = 2.6-6.3), corpus uteri (O/E = 11.91, 95% CI = 7.3-18.4), colon (O/E = 17.9, 95% CI = 11.1-27.3), and ovary (O/E = 4.9, 95% CI = 2.7-8.2); no increased risk was found for women aged >/=50 years. Ovarian cancer risk remained elevated following all of these first primary cancers 5-9 years after diagnosis; for women with breast and colon cancer, risk remained elevated 15-24 years after diagnosis. A significant increased risk was found for all of these cancers among white women <50 years at diagnosis; risk was increased among black women <50 years with cancer of the breast, cervix, and colon.CONCLUSIONS: We found an ovarian cancer risk higher than expected for women with certain types of cancer; however, the risk was limited to women <50 years of age.     

Lung cancer risk associated with cancer in relatives

Family history data from an incident case-control study of lung cancer conducted in the Texas Gulf Coast region between 1976 and 1980 were analyzed to evaluate the contribution of cancer in first-degree relatives to lung cancer risk. Odds ratios (OR) increased slightly as the number of relatives with any cancer increased (reaching 1.5 with 4 or more relatives with cancer). Risks were higher for tobacco-related cancers (OR = 1.5 for 2 or more relatives with these tumors) and greatest for first-degree relatives with lung cancer (OR = 2.8 for lung cancer in 2 or more relatives). For cases of squamous cell carcinoma and adenocarcinoma of the lung, risks with 3 or more relatives with any cancer were increased 2-fold (OR = 1.8 and 1.9 respectively), and a significantly elevated risk was found for having a first-degree relative with lung cancer for each histologic type (ORs from 1.7-2.1). Having a spouse with lung cancer increased lung cancer risk (OR = 2.5), and cases with lung cancer reported in a first-degree relative were diagnosed at an earlier age, as were case siblings with lung cancer.