After older patients undergo lung resection for stage I non–small-cell lung cancer, they are actually at greater risk of death from something other than lung cancer for up to 2.5 years, according to researchers at Memorial Sloan Kettering Cancer Center, New York. The findings were published online in the Journal of Clinical Oncology (2016;34: doi: 10.1200/JCO.2016.69.0834).
“As age increases, the risk of competing events increases, such as death from noncancer diseases,” wrote Takashi Eguchi, MD, and coauthors. “In this era of personalized cancer therapy, important to the stratification of individualized treatments is the determination of how both cancer and noncancer risk factors – specifically, comorbidities associated with increasing age – contribute to the risk of death.”
The researchers examined outcomes in three different age groups: younger than 65, 65-74, and 75 and older. The study focused on 2,186 patients with pathologic stage I non–small-cell lung cancer (NSCLC) among a population of 5,371 consecutive patients who had resection for primary lung cancer from 2000 to 2011. Seventy percent of patients in the study group were 65 and older, and 29.2% were 75 and older.
In all age groups, the calculated 5-year cumulative incidence of death (CID) for lung cancer–specific causes exceeded that for noncancer causes, but at significant intervals the 65-and-over groups were more likely to die from the latter. For the overall study group, noncancer-specific causes accounted for a higher CID through 18 months after surgery, when the CID for both cancer and noncancer causes crossed at around 2.9. At 5 years, the overall lung cancer–specific CID was 10.4 vs. 5.3 for noncancer specific causes.
However, in the older age groups, those trends were more pronounced. In those aged 65-74, CID for both causes met at around 3.15 at 18 months (10.7 for lung cancer–specific and 4.9 for noncancer specific at 5 years), whereas for those 75 and older, CID for noncancer causes exceeded that for lung cancer–related causes for 2.5 years, when both were around 6; reaching 13.2 for lung cancer–specific and 9 for noncancer-specific at 5 years.
In the 65-and-younger group, lung cancer– and noncancer-specific CIDs were equal for about 3 months after surgery, when the lung cancer deaths tracked upward and the trends diverged (at 5 years, CID was 7.5 for lung cancer–specific and 1 for noncancer specific).
“We have shown that in patients with stage I NSCLC, the majority of postoperative severe morbidity, 1-year mortality, and 5-year noncancer-specific mortality were attributable to cardiorespiratory diseases,” Dr. Eguchi and colleagues said.
“We have also shown that short-term mortality is primarily attributable to noncancer-specific diseases.” The findings underscore the importance of screening older patients for noncancer-specific diseases that could alter outcomes, the researchers said.
Of the 2,186 stage I NSCLC patients in the study, 167 developed severe morbidities after surgery; 68.3% developed respiratory problems and 18.6% went on to develop cardiovascular problems. Patients who had lobectomy were more likely to develop respiratory problems than were those who had sublobar resection, Dr. Eguchi and coauthors said.
Respiratory and cardiovascular diseases were the most frequent causes of death early after surgery. At 30 days, respiratory disease accounted for 5 deaths and cardiovascular disease 7 of 15 total deaths at 30 days; and at 90 days, 11 and 7, respectively, of 27 overall deaths. Even at 1 year, noncancer issues were the leading cause of death (50%), followed by lung cancer–specific causes (27.8%) and other cancer specific disease (13.3%).
“Noncancer-specific mortality represents a significant competing event for lung cancer–specific mortality, with an increasing impact as age increases,” Dr. Eguchi and coauthors said. “These findings can provide patients with more accurate information on survivorship on the basis of their individual preoperative status and help determine patients’ optimal treatment options.”
The study received financial support from coauthor Prasad S. Adusumilli, MD. Dr. Eguchi and Dr. Adusumilli and the other coauthors had no relevant financial disclosures.