The Concept of Cure Vincent T Devita, Jr

EDITORIAL

www.nature.com/clinicalpractice/onc The concept of cure Vincent T DeVita, Jr

For many chronic diseases, none of the affected It’s time we pay occurs frequently, usually by doctors who patients have the prospect of a complete cure, more, not less, never had the confidence that they could cure and patients have to learn to live with their dis- patients in the first place. Doctors who devi- ability. Cancer does not fall into this category; attention to ate from using established regimens avoid any it is the most curable of the chronic diseases. the concept of certainty in predicting outcome, to the patient’s Why, then, all the concern these days about cure and give detriment. “Rarely recurs” seems clear enough; using the word ‘cure’ when discussing treat- patients the despite a diminishing risk of relapse over time, ment outcome with patients? The recent benefit of the some patients’ tumors inexplicably recur after impressive results of the adjuvant trastuzumab long periods in remission. This does not negate (Herceptin®, Genentech Inc., San Francisco, doubt. the fact that most patients followed over the CA) chemo therapy breast cancer study (Nat same period are cured. Patients understand Clin Pract Oncol 3: 12–13) prompted one inves- this risk if the odds are carefully explained to tigator to talk about the “cure of breast cancer”, them. Other issues such as employment, insur- which triggered many news stories expressing ance, working in the uniformed services and concerns about “over promise”. In fact, for providing for a family also revolve around the decades, we have been curing an increasing confidence in cure expressed by physicians. number of patients with breast cancer, and, By failing to call a cure a cure we also with the addition of this new adjuvant program, sometimes blind ourselves to unique opportu- we will be curing many more. In part, this is why nities. For example, despite the fact that com- mortality rates from breast cancer are falling in plete remission can be attained using standard the US and elsewhere in the world. The grand chemotherapy in a significant fraction of patients experiments of the 1960s, using childhood with advanced breast cancer, almost all such leukemia and Hodgkin’s disease as experi- patients relapse and die of their disease. But, mental models, focused solely on addressing some patients who had advanced breast cancer whether advanced cancers were curable by are long survivors—invariably patients who were chemotherapy. The answer was yes, and this treated with myeloablative chemotherapy, sup- led to the use of adjuvant chemotherapy in the ported by autologous marrow transplantation. first place. I recently heard about a follow-up of such a For almost all cancers, the risk of recurrence study, originally published in 2000, (Biol Blood is clear from the shape of the relapse-free sur- Marrow Transplant 6: 262–271) which used vival curves. For cancers curable by chemo- purified, autologous adult marrow stem cells, therapy, and treated appropriately, relapse devoid of contaminating tumor cells, to sup- rates diminish over time, and disease rarely port chemotherapy. At 7.5 years of follow-up, recurs after a specified period; this period 32% of patients are alive and continuously free is unique to each type and stage of cancer. of disease (I Weissman, personal communica- After that specified time, patients in remission tion). The rate of relapse in this study diminished should be considered cured. In other cancers, VT DeVita, Jr is considerably and was uniquely different from the relapse rate is steady and linear and while the Editor-in-Chief the relapse rate after standard chemotherapy. long survival might be possible, cure is not of Nature Clinical Comparison with relapse-free survival curves achieved with current treatments. Practice Oncology. indicates that these patients can be considered Two phrases are key to this concept— cured. Failure to recognize the ability to cure led “treated appropriately” and “rarely recurs”. If Competing interests to the premature abandonment of studies of this The author declared he has doctors do not adhere to an established regi- no competing interests. treatment approach. It’s time we pay more, not men, the true outcomes will most likely not less, attention to the concept of cure and give www.nature.com/clinicalpractice be as expected. Unfortunately this scenario doi:10.1038/ncponc0422 patients the benefit of the doubt.

FEBRUARY 2006 VOL 3 NO 2 NATURE CLINICAL PRACTICE ONCOLOGY 59