Most oncologists accept the prevailing theory that cancer is the result of "invading alien enemies that must be completely destroyed in order to achieve the cure", say Michael Retsky, from the Harvard School of Public Health, and Michael Baum, from the Royal Free Hospital and UCL Medical School in London, along with three other cancer specialists.
However, there is virtually no evidence to support the theory, which has been the accepted model since the 1890s. Instead, there's a great deal of evidence-such as mammography screening results, and the outcomes of chemotherapy, surgery and radio-therapy-to suggest that the disease is chaotic. It also has long periods when it lies dormant, say the experts in their landmark, 32-page review (Cancers, 2010; 2: 305-37).
Breast cancer surgery is usually performed-unwittingly-during the disease's dormant period. The inter-vention then often reactivates the cancer, causing it to suddenly spread rapidly-and often fatally. In general, this is a common outcome, as it follows more than half of all surgical procedures for breast tumours.
"Millions of healthy women have been screened for cancer and cancer patients have been treated by inter-ventions based on the continuous growth assumption," says the report.
Yet, even DCIS (ductal carcinoma in situ), often considered an early marker of breast cancer, rarely becomes cancer, even though its detection by mammography invariably triggers early, and aggressive, treatment.
"The DCIS conundrum is rarely disclosed in public since it is thought that, if women were told this, they might not opt for mammography. Getting women screened . . . is a major goal of some organizations so this information is withheld as its release will be contrary to achieving their goal. This is highly patronizing to women. It has been described as 'Mummy knows best'," they write.
First, do nothing
The DCIS paradox is just one example that confounds the continuous-growth concept of cancer. Another one is the cancer patient who is never treated. While it is rare to find such a case, one study carried out between 1938 and 1956 in Ontario, Canada, did succeed in tracking untreated cancer patients. Out of nearly 10,000 cancer patients, researchers found 145 who had received no treatment whatsoever.
While the continuous-growth model of cancer suggests that the untreated patients would inevitably die, 35 per cent of these patients were still alive five years later, and their average survival rate was 47 months, nearly four years. In addition, 70 per cent of those whose cancer did not spread were still living five years later. By way of comparison, the overall survival rate among women was around 45 per cent and, in men, 36 per cent (Can Med Assoc J, 1965; 92: 647-51).
Astonishingly, doing nothing at all has a better survival rate than the use of conventional therapies. Radical surgery-removing the tumour 'with its roots', including the lymph nodes-has a 25-per-cent survival rate (Cancer, 1983; 51: 1941-3). This procedure has given way to a gentler, systemic treat-ment based on the hypothesis that cancer is spreading through the bloodstream even before it is detected. However, systemic therapy has a similarly poor outcome, reducing the rate of breast cancer deaths by only 8 per cent (Lancet, 1992; 339: 1-15, 71-85).
Radiotherapy reduces the breast cancer death rate by 3 per cent-but any good that it does is counteracted by the harm from radiation to the heart. Similar numbers who survive the cancer go on to die instead of heart problems due to radiation, especially if the cancer was in the left breast (N Engl J Med, 1997; 337: 949-55).
Earlier trials suggested that chemo-therapy was the way forward with cancer treatment, but later studies were far more modest. One report found an "absolute survival benefit"of 11 per cent in women aged under 50 vs 3 per cent in women aged 50 to 69 with node-involving breast cancer (Oncology, 2000; 14: 1267-88).
Faced with such disappointing out-comes, oncologists adopted a response similar to that taken by surgeons a few decades earlier: if a little doesn't work, try a lot. However, according to Retsky et al., "High-dose chemother-apy with bone marrow rescue was a failure, and the least said about this sorry episode in the history of breast cancer the better."
How cancer develops
The failure of conventional therapies suggests that the idea of cancer as aggressive and ongoing abnormal cell growth is faulty. Close observation of the disease shows periods of growth and dormancy. In patients with breast cancer, researchers saw a growth spurt at 18 months, followed by a dormant stage peaking at 50 months. This was followed by further growth that peaked at 60 months that finally ended with a long tail-off of almost no growth lasting for up to 20 years in untreated patients (Ann Oncol, 1997; 8: 1075-80).
However, this pattern is disturbed by treatment, especially surgery. In studies of breast cancer detected by mammography, death rates peaked in the third year in women aged under 50 who had been operated on within a year of diagnosis. However, deaths in women aged 50 and older with no surgery did not rise at any time (Lancet, 2002; 359: 909-19). This suggests that the surgery was responsible for the higher death rates in those women.
A new model
Retsky and his co-authors are calling for the adoption of a new model of cancer that, in turn, would change the way it is managed and treated.
"Cancer is a process," they argue. "Individual cancers, while likely to originate from single cells, are constantly adapting to the local environment."
Their new model also acknowledges cancer's various phases of growth and dormancy. The dormant phase often ends because of a signal-from sur-gery or perhaps an adverse life event-that triggers a period of rapid growth. "The act of wounding the patient creates a favourable environment for the sudden transfer . . . from a latent to an active phase," they say.
According to the new model, sur-gery and other interventions would not be performed as a matter of urgency following diagnosis, as the timing of such interventions would be determined by the phase of the cancer. Surgery would be performed only during the cancer's active phase and, even then, procedures would be in place to prevent flooding the body with angiogenic (stimulating blood-vessel growth) signals. Any positive effects of cancer drugs such as tamoxifen and chemotherapy might be because they have anti-angiogenic effects rather than because of any direct effect on the cancer cells themselves.
WDDTY VOL. 21 ISSUE 6