Should I be Tested for Cancer? Maybe Not and Here’s Why
Posted by medconsumers on June 10, 2004
New Book by H. Gilbert Welch: Should I be Tested for Cancer
Americans are keen on cancer screening. In fact a recent survey showed that most would rather have a free whole-body scan than $1,000 in cash. 32% thought that an 80-year-old man who chose not to undergo a colonoscopy was irresponsible. And 74% believe that finding cancer early saves lives “most or all of the time.” Even the common occurrence of an anxiety-producing false alarm, experienced by 38% of those surveyed, did not blunt enthusiasm for cancer screening. Nearly all who had this experience acknowledged its terror-inducing aspect, but were glad they had been tested.
Cancer testing for symptom-free people is accepted as a must-do health maintenance ritual by most Americans, but are they undergoing screening with eyes wide open? How many women, for example, have ever had the pros and cons of Pap testing explained to them? How many even know there is a downside to a Pap test? But screening for any disease is a two-edged sword carrying risks as well as benefits. And sometimes the former cancels out the latter.
One of the authors of the above-mentioned survey, which was published early this year in the Journal of the American Medical Association, is H. Gilbert Welch, MD, MPH, Professor in the Departments of Medicine and Community and Family Medicine at Dartmouth Medical School. Dr. Welch’s new book entitled, Should I be Tested for Cancer? Maybe not and here’s why, serves as a counterbalance to the one-sided information the public receives from their physicians and organizations like the American Cancer Society. (“Your life will be saved.” “Your treatment will be less drastic.”) In fact, his book is downright subversive, as its title suggests consumers can make an informed decision not to be screened.
Dr. Welch writes that his book is for people who “are open to questioning the wisdom of these testing efforts.” It is not for people who need to have simple answers. “None of us likes uncertainty–but this book is full of it.” He describes cancer as a disease that is not inevitably fatal, or even inevitably invasive. Before screening, it helps to know your odds of getting the target cancer. Typically, people are told a given test reduces the odds of dying of cancer by 30%. Dr. Welch says such statistics mean nothing unless you know your odds of getting the target cancer. As an example, he provides a graph based on the mammography screening trials. In the next ten years, of 1,000 American women age 50, six will die of breast cancer without mammography; four will die of breast cancer despite having had mammograms. Therefore, only two out of 1,000 will avoid a breast cancer death because of mammography. His explanation provides not only a realistic expectation of mammography’s benefit but it also illustrates the low odds of dying of breast cancer. News flash: Most women will never get it!
The colon cancer screening trials show a puzzling finding that is rarely conveyed to the public. The people who were randomly assigned to be screened showed a modest drop in colon cancer deaths, compared to the people who were not screened. However, the same trials showed that this benefit was canceled by an inexplicable increase in deaths from other causes, chiefly heart disease.
Screening tests are good at finding something Dr. Welch calls pseudodisease, and unnecessary treatment is the usual consequence. It is the PSA-detected prostate cancer that would have remained dormant, but is usually treated with radical prostatectomy; it is the nodule found during a lung scan that demands a biopsy to rule out cancer; it is the mammography-detected ductal carcinoma of the breast that automatically means breast removal in some areas of the country.
Some high-tech screening procedures are so sensitive that they identify lumps in nearby organs. Dr. Welch relates a written account of a doctor who underwent a virtual colonoscopy, which can “see” beyond the colon. It turned up a kidney mass, a 2 cm liver mass and multiple non-calcified nodules in the lung. After several CAT scans, a liver biopsy, removal of three small sections of his lung, four days of potent painkillers, he began to feel “nearly normal” five weeks later, except for the rib pain caused by the surgical interruption of the nerves during the lung biopsies. “No cancer” was the outcome. The doctor/patient may have been relieved, observed Dr. Welch, but he was also motivated to start asking hard questions about radiologists and their remarkably sensitive imaging tests. “His story certainly makes one wonder whether they are seeing too much.”
Maryann Napoli, Center for Medical Consumers© June, 2004