Non-lethal cancers, spontaneous remissions, people with genetic risk factors who don’t get cancer in their lifetime - these things are neither mystical nor miraculous; they are medical facts. Yet, there are few subjects that make mainstream physicians more nervous or uncomfortable than the idea of cancers that cure themselves.
Most cancer treatments are doled out on the assumptions that cancer is: a) always aggressive and life-threatening; and b) that it won’t get better on its own.
But how sound are these seemingly basic assumptions?
A recent letter to The Lancet dared to suggest that a particular form of breast cancer - ductal carcinoma in situ - may simply burn itself out in time (Lancet, 2002; 360: 1101). The authors noted that a local regression (in other words, spontaneous healing) of this relatively mild form of cancer was first described 70 years ago (J Pathol Bacteriol, 1934; 38: 117-24) and has also been noted in some textbooks (Rosen PP, Rosen’s Breast Pathology, 2nd edn, Philadelphia: Lippincott Williams & Wilkins, 2002), but has otherwise been largely ignored by the medical profession.
The authors, scientists at the Western Australia Centre for Pathology and Medical Research, say that in their experience of six years of performing core biopsies of DCIS, they often discover microcalcification lesions - areas of breast tissue that were probably once cancerous, but where the cancer has burnt itself out. They are not sure if high-grade DCIS could burn itself out in the same way, but the mere existence of such lesions has profound implications for those attempting to devise appropriate treatments for individual cancers (see box, p 3).
Apart from the impact that it can have on the patient’s life, treating non-threatening cancers provides a high ‘feel-good’ factor for doctors. Normally impotent in the face of this perplexing disease, doctors who get a good result with a low-grade cancer may feel as if they are achieving something, which adds to the illusion that we really are ‘winning the war’ against cancer.
Because of medicine’s inability to distinguish between the life-threatening and non-threatening cancers, patients with a positive diagnosis are often given the full force of medical treatment: surgery, irradiation and drugs for cancers that might not have been a threat to their lives in the first place.
What’s more, all conventional treatments further weaken the immune system - an important factor since immune competence may be an important aspect in encouraging spontaneous remissions.
Sometimes, a conventional treatment works - but no one knows why. While no one would wish to give false hopes of a spontaneous remission to someone suffering from cancer, the fact is that spontaneous remissions do occur - perhaps more often than we realise and maybe even without our ever knowing it. In fact, cancer can develop in the body, but be kept so well in check by our own biological processes that it will cause no ill effects whatsoever.
Prostate cancer is often a slow-growing condition that is not necessarily life-threatening. Other types of tumours, such as sarcomas, are also generally slow to grow.
Unfortunately, doctors are often ill-equipped to discriminate between slow-growing, less aggressive cancers and those that are aggressive and life-threatening. This is the ‘X factor’ that prompts doctors to advise regular screening programmes and, on detection of a potential cancer, swift treatment with chemotherapy and radiation treatment.