Cancer

Aging population means more cancer cases

The Canadian Cancer Society estimates there will be 132,000 new cases of cancer and 65,000 cancer-related deaths in Canada during 2000. Age-standardized rates for new cancer cases have remained relatively stable for the past 30 years, but the number of new cases has grown steadily (from 51,000 in 1971) because of the aging population. CMAJ 2000;163(1):77.

Burnout of cancer care workers

Amid growing concern over anecdotal reports of cancer care workers suffering burnout, researchers surveyed 1,016 physicians, allied health care professionals and support staff in the Ontario cancer care system about job stress. The results are alarming. About one-third of the respondents in each group reported considering leaving their jobs. The authors say this is bad news for a cancer-treatment system in which highly trained and experienced workers are already in short supply. Emotional, work-related exhaustion was reported by 53.3% of the physicians, 37.1% of the allied health care professionals and 30.5% of the support staff. The authors caution that these findings could have a profound impact on the quality of care these individuals are able to provide for patients. CMAJ 2000;163(2):166-9.

Prostate cancer treatment: a roadmap

The incidence of prostate cancer is increasing, as is the number of diagnostic and therapeutic interventions to manage this disease. Researchers have developed the Montreal Prostate Cancer Model to follow a hypothetical cohort of men to estimate the probability of prostate cancer and the annual progression of the disease according to patient age, tumour stage and grade, and initial treatment. The model’s 10-year disease-specific survival estimates following prostatectomy for tumour grades 1, 2 and 3 were 96%, 92% and 84% respectively. In comparison, data from the Surveillance, Epidemiology and End Results (SEER) Program, based on more than 59,000 cases of localized prostate cancer, show rates of 98%, 91% and 76%, respectively.

Given the comparable results, the authors conclude that the Montreal Prostate Cancer Model can be used to guide decision-making for the management of prostate cancer and to forecast clinical outcomes for men with prostate cancer or who are at risk for the disease. CMAJ 2000;162(7):977-83.

An accompanying article used the model to estimate the economic burden of prostate cancer. In a 1997 cohort of 5.8 million Canadian men aged 40 to 80 years prostate cancer would eventually be diagnosed in an estimated 701,491 men (12.1%) over their lifetime, and the direct medical costs would total $9.76 billion. CMAJ 2000;162(7):987-92.

A related commentary suggested that society should collectively invest in such disease-simulation models, rendering them public tools, in order to facilitate scientific scrutiny and replication. CMAJ 2000;162(7):1001-2.

Screening controversy

While the results of three randomized control trials showing a decrease in colon cancer mortality with fecal occult blood screening have prompted some provincial cancer agencies to recommend screening for certain individuals, others remain sceptical that screening large groups of people is cost effective. In this debate about the issue, one researcher takes the call for broad screening to task, arguing that 1,000 people would need to be screened for about 10 years to prevent a single death from colon cancer. CMAJ 2000;163(5):548.

Two other researchers disagree, saying that by their calculations 12,325 life-years would be saved for every 100,000 people screened. CMAJ 2000;163(5):543-4 and 547.

Screening for lung cancer

Lung cancer tends to be a symptom-prompted diagnosis, discovered at an advanced stage, with an overall death rate of 90%. Currently agencies in Canada and the United States recommend against screening for lung cancer. When baseline data from the Early Lung Cancer Action Project (ELCAP) demonstrated that CT scanning is greatly superior to traditional radiography at detecting asymptomatic lung cancer, the National Cancer Institute developed plans for a long-term randomized controlled trial (RCT) to measure the life-saving effectiveness of screening for lung cancer.

But this trial is redundant according to a McGill researcher, because the cost-effectiveness of screening for lung cancer can already be deduced. In the ELCAP study, 23 (70%) of the 31 cases of lung cancer detected were stage IA, which has a curability rate of 70%. The author therefore argues that the curability rate among cases diagnosed through screening would be about 50%. The cost of one CT scan is about $200. By deducing a case-detection rate of 0.5%, a reduction in overall mortality of 40 percentage points (from 90% to 50%) and perhaps a 10-year gain in the patient’s life expectancy, the researchers calculate that the gain in life expectancy from a single repeat screen would be 0.02 years. The cost per life-year gained would be $10,000 ($200/0.02). We don’t need an RCT to prove that suitably specified CT screening for lung cancer would be cost-effective — we already know it, argued the researcher. CMAJ 2000;162(10):1431-6.

Copyright 2000 Canadian Medical Association or its licensors