New Cancer Survival Data Contains Reasons for Optimism
New data recently published in the Journal of Clinical Oncology
has provided a degree of hopeful news to oncologists and their patients, suggesting that progress is being made in the fight against cancer and that a number of trends are pointing toward continued gains. Ronald M. Bukowski, MD, Director of the Experimental Therapeutics Program, Cleveland Clinic Taussig Cancer Center and Professor of Medicine at the Cleveland Clinic Foundation Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, noted that “in most cancers evaluated, a marked increase in five-year as well as 10-year survival rates were observed.”
Study authors Hermann Brenner, Adam Gondos, and Volker Arndt estimated trends in five- and ten-year relative survival of United States cancer patients in the period from 1998 to 2003. Data for the project, entitled, “Recent Major Progress in Long-Term Cancer Patient Survival Disclosed by Modeled Period Analysis,” was derived from the 1973 to 2003 database of the Surveillance, Epidemiology, and End Results Program. According to researchers, the recently introduced modeling techniques that were employed facilitated up-to-date and precise survival estimates.
Survival rates are impacted differently depending on the individual type of cancer in question. To illustrate this point, Dr. Bukowski highlighted the example of kidney cancer. “Kidney cancer is one of the solid tumor (cancers) where there clearly was an improvement (as demonstrated by the JCO study data) in five year survival,” stated Dr. Bukowski, “In fact, there were clear improvements in both five- and ten-year survival rates. The distribution that was looked at appeared to be pretty consistent in terms of stages of disease. The several issues that were raised as to why (this was the case) generally mirror the other cancers (i.e., lifestyle improvements, diagnostic advancements).” However, in several respects, as Dr. Bukowski pointed out, “kidney cancer is unique.”
For example, the role of improved diagnosis has probably played a larger role in kidney cancer than it has in many other malignancies. During the study period, reported Dr. Bukowski, “there was a significant increase in incidental diagnosis of renal tumors. For example, a patient may complain of abdominal pain and receive a CAT scan. This, in addition to the utilization of other imaging technologies, has become a very common way that renal tumors are found.” As a result of more aggressive and expanded opportunities for diagnosis, Dr. Bukowski stated, “Oncologists, on average, are seeing smaller tumors than they were seeing in the past.” This means that renal tumors are being caught in earlier stages of progression. As a result, the data reflect this more favorable stage distribution. “Smaller renal tumors result in better outcomes,” explained Dr. Bukowski.
In addition, explained Dr. Bukowski, whereas other cancer survival rates may have improved as a result of clinical progress, “recent therapeutic advances (in the field of renal cancer) have yet to show up (in the published data).”
According to Dr. Bukowski, the fact that the JCO kidney cancer data does not reflect the benefits derived from the evolution of oncologic therapy is likely a harbinger that more positive survival data are on their way in the future, not just in the realm of kidney cancer but in a number of other major cancers as well. Although data reflecting therapeutic advances “remains to be demonstrated in patients with advanced (renal) disease, (further improvements in survival data as a result) are probably forthcoming. We haven’t seen it yet, but I suspect we will.” Dr. Bukowski pointed to a “parallel and analogous situation” evident in several other major cancers “such as colon cancer and breast cancer, to cite two prominent examples” in which “a number of new drugs have been approved but have been approved relatively recently (that is, following the period of data collection for the JCO study) so one wouldn’t see an impact in terms of survival data.”