Cancer and construction: what occupational histories in a Canadian community reveal.

From 2000 to 2002, male patients at a Canadian cancer treatment center with new-incident head-and-neck or esophageal cancers were invited to participate in a population-based study. The study population included 87 cases and 172 controls. A lifetime-history questionnaire was administered. Odds ratios (ORs) were calculated for occupational groups with a minimum of five cases, adjusted for duration of employment, age, smoking, alcohol, education, and income. A significantly increased risk was shown for construction workers (OR = 2.20; 95% CI 1.25-3.91). This investigation of a set of rare cancers over a limited time period demonstrates the feasibility of this research approach. The increased risk among construction workers supports the need for more comprehensive study of exposures in this occupational group.

Occupation and breast cancer: a Canadian case-control study.

A local collaborative process was launched in Windsor, Ontario, Canada to explore the role of occupation as a risk factor for cancer. An initial hypothesis-generating study found an increased risk for breast cancer among women aged 55 years or younger who had ever worked in farming. On the basis of this result, a 2-year case-control study was undertaken to evaluate the lifetime occupational histories of women with breast cancer. The results indicate that women with breast cancer were nearly three times more likely to have worked in agriculture when compared to the controls (OR = 2.80 [95% CI, 1.6-4.8]). The risk for those who worked in agriculture and subsequently worked in automotive-related manufacturing was further elevated (OR = 4.0 [95% CI, 1.7-9.9]). The risk for those employed in agriculture and subsequently employed in health care was also elevated (OR = 2.3 [95% CI, 1.1-4.6]). Farming tended to be among the earlier jobs worked, often during adolescence. While this article has limitations including the small sample size and the lack of information regarding specific exposures, it does provide evidence of a possible association between farming and breast cancer. The findings indicate the need for further study to determine which aspects of farming may be of biological importance and to better understand the significance of timing of exposure in terms of cancer risk.

Randomized trial of breast irradiation schedules after lumpectomy for women with lymph node-negative breast cancer.

BACKGROUND: Breast irradiation after lumpectomy is an integral component of breast-conserving therapy that reduces the local recurrence of breast cancer. Because an optimal fractionation schedule (radiation dose given in a specified number of fractions or treatment sessions over a defined time) for breast irradiation has not been uniformly accepted, we examined whether a 22-day fractionation schedule was as effective as the more traditional 35-day schedule in reducing recurrence. METHODS: Women with invasive breast cancer who were treated by lumpectomy and had pathologically clear resection margins and negative axillary lymph nodes were randomly assigned to receive whole breast irradiation of 42.5 Gy in 16 fractions over 22 days (short arm) or whole breast irradiation of 50 Gy in 25 fractions over 35 days (long arm). The primary outcome was local recurrence of invasive breast cancer in the treated breast. Secondary outcomes included cosmetic outcome, assessed with the European Organisation for Research and Treatment of Cancer (EORTC) Cosmetic Rating System. All statistical tests were two-sided. RESULTS: From April 1993 through September 1996, 1234 women were randomly assigned to treatment, 622 to the short arm and 612 to the long arm. Median follow-up was 69 months. Five-year local recurrence-free survival was 97.2% in the short arm and 96.8% in the long arm (absolute difference = 0.4%, 95% confidence interval [CI] = -1.5% to 2.4%). No difference in disease-free or overall survival rates was detected between study arms. The percentage of patients with an excellent or good global cosmetic outcome at 3 years was 76.8% in the short arm and 77.0% in the long arm; the corresponding data at 5 years were 76.8% and 77.4%, respectively (absolute difference = -0.6%, 95% CI = -6.5% to 5.5%). CONCLUSION: The more convenient 22-day fractionation schedule appears to be an acceptable alternative to the 35-day schedule.

An international comparison of breast cancer survival: Winnipeg, Manitoba and Des Moines, Iowa, metropolitan areas.

PURPOSE: Extending previous Canadian-United States cancer survival comparisons in large metropolitan areas, this study compares breast cancer survival in smaller metropolitan areas: Winnipeg, Manitoba and Des Moines, Iowa. METHODS: Manitoba and Iowa cancer registries, respectively, provided a total of 2,383 and 1,545 women with breast cancer (1984 to 1992, followed until December 31, 1997). Socioeconomic data for each person's residence at the time of diagnosis was taken from population censuses. RESULTS: Socioeconomic status and breast cancer survival were directly associated in the US cohort, but not in the Canadian cohort. Compared with similar patients in Des Moines, residents of the lowest fifth of income areas in Winnipeg experienced a significant 5-year survival advantage (survival rate ratio [SRR] = 1.14). In these lowest income areas, the Canadian survival advantage was larger among women aged 25 to 64 years (SRR = 1.23), and this was observed in the middle fifth of income areas among this younger cohort (SRR = 1.11). The Canadian survival advantage even seemed apparent in the poorest neighborhoods with relatively high representations of Aboriginal people (SRR = 1.16). CONCLUSION: This study replicated the finding of advantaged Canadian cancer survival in smaller metropolitan areas that had been consistently observed in larger metropolitan areas. Canada's single payer health care system seems to offer similar advantages across a number of diverse urban contexts.

Occupational histories of cancer patients in a Canadian cancer treatment center and the generated hypothesis regarding breast cancer and farming.

Occupational exposures increase cancer risks. The Windsor Regional Cancer Centre in Windsor, Ontario, was the first Canadian cancer treatment center to collect the work histories of its patients, which were recorded using a computer-based questionnaire. Breast cancer cases represented the largest respondent group. The lifetime occupational histories of 299 women with newly diagnosed breast cancers were compared with those of 237 women with other cancers. Odds ratios (ORs) were calculated using logistic regression, adjusting for age, social class, and education. The OR for women < or = 55 years of age with breast cancer who had ever farmed, compared with women of the same age with other cancers, was 9.05 (95% CI 1.06, 77.43). Patients' occupational histories can help to inform understanding of cancer etiology and prevention. This effort points to a need for investigation of the possible association between breast cancer and agricultural hazards such as pesticides.

A pilot study evaluating the safety and microbiologic efficacy of an economically viable antimicrobial lozenge in patients with head and neck cancer receiving radiation therapy.

BACKGROUND: Mucositis occurs in almost all radiotherapy-treated head and neck cancer patients, in approximately 75% of patients receiving hematopoietic marrow transplantation, and in approximately 40% of all patients who receive chemotherapy. Mucositis is painful, may affect all oral functions, and is a dose- and rate-limiting toxicity of therapy for cancer. Radiation-associated mucositis (onset, intensity, and duration) has been shown in recent clinical trials to be modified by the use of antibacterial/antifungal lozenges. PURPOSE: The aim of this collaborative two-center phase II study was to assess the toxicity and microbiologic efficacy of an economically viable antimicrobial lozenge in the management of patients receiving radiation therapy for head and neck cancer. MATERIALS AND METHODS: Seventeen patients scheduled to receive radical or postoperative radiotherapy were provided with bacitracin, clotrimazole, and gentamicin (BCoG) lozenges (one lozenge dissolved in the mouth qid from day 1 of radiotherapy until completion). Ease of use and palatability of the lozenges, patients' symptoms (swallowing and pain), and quantitative and qualitative microbiologic evaluation of an oral rinse collection was conducted at least once weekly during radiation therapy. RESULTS: No significant side effects were reported from the use of the lozenges. The lozenges were well tolerated at the beginning of treatment by all patients, with some minor difficulty associated with oral discomfort toward the end of the treatment. Microbiologic evaluation showed consistent elimination of yeast organisms in all patients. In four patients there was no growth of gram-negative bacilli on culture, whereas in two patients, fluctuating counts were seen, and one patient had increased counts. The remaining patients had significant reduction in the gram-negative bacilli counts. CONCLUSIONS: This study demonstrated that the BCoG lozenge is tolerable and microbiologically efficacious, achieving elimination of Candida in all patients and reduction in gram-negative flora in most patients. A phase III study is underway to evaluate the clinical efficacy of this lozenge.