Mammograms may detect some cancers that would have otherwise regressed [Archive]

gdpawel

11-24-2008, 11:22 PM

Dr. Robert M. Kaplan, chairman of the department of health services at the School of Public Health at the University of California, Los Angeles, who with his colleague, Dr. Franz Porzsolt, an oncologist at the University of Ulm, wrote an editorial that accompanied the study, were persuaded by the analysis, and feel the implications are potentially enormous.

Dr. Barnett Kramer, director of the Office of Disease Prevention at the National Institutes of Health, had a similar reaction. People who are familiar with the broad range of behaviors of a variety of cancer, know spontaneous regression is possible, but what is shocking is that it can occur so frequently.

And Donald A. Berry, chairman of the department of biostatistics at M. D. Anderson Cancer Center said the study increased his worries about screening tests that find cancers earlier and earlier. Unless there is some understanding of the natural history of cancers that are found, the result can easily be more and more treatment of cancers that would not cause harm if left untreated.

Dr. Berry felt that it's possible that we all have cells that are cancerous and that grow a bit before being dumped by the body. Screening tests may pick up minute tumors that would not progress and might even go away if left alone (pseudodisease). Patients will be alarmed and exposed, perhaps needlessly, to the risks of chemotherapy, surgery and radiation.

Spontaneous remissions in cancer suggests that the body can heal itself. It seems like most apparently occur in just a few types of malignancies: malignant melanoma, renal cell cancer, low-grade non-Hodgkin's lymphoma, chronic lymphocytic leukaemia and neuroblastoma in children. However, spontaneous remissions do occur in vastly different other types of cancers.

The very existence of spontaneous remissions represents a threat to some in the cancer industry. But such anomalies can pave the way to a better understanding of the causes of cancer which can then lead to rational therapies. Historical observations of spontaneous remissions of breast cancer after the onset of menopause lead to approaches of hormonal treatment which is a mainstay of adjuvant and palliative therapy in breast cancer.

Regardless, spontaneous remissions represent an important clue as to how the body can defend itself against cancer. Researchers should think "outside the box" at this important phenomenon rather than see it as a threat to their conventional thinking and appreciate the insight it may provide to rational approaches to cancer treatment.

For some common cancers, it is not clear that early detection and treatment actually prolong patients' lives. Early detection may just mean patients spend a longer time knowing they have cancer, and yet die at the same time they would have died anyway if the tumor had been diagnosed later. A decision to forgo cancer screening can be a reasonable option.