Adjuvant chemotherapy may improve lung cancer outcomes in older patients
Adjuvant chemotherapy may improve survival for older patients with stage I non–small cell lung cancer, according to an analysis of the SEER–Medicare database.
However, the regimen also is associated with serious adverse events, according to an analysis of the SEER-Medicare database.
Weighing the risks vs. benefits of adjuvant chemotherapy is more difficult in older patients, as they have a greater risk for disease recurrence after surgical resection but also have a more limited life expectancy.
Jyoti Malhotra, MD, of the department of hematology and oncology at Tisch Cancer Institute at Icahn School of Medicine at Mount Sinai, and colleagues conducted a population-based study to compare survival and rates of serious adverse events among elderly patients with T2N0 NSCLC. The analysis included 3,289 patients aged older than 65 years who were treated between 1992 and 2009. All patients had tumors at least 4 cm, and they underwent surgical resection followed by either observation or adjuvant platinum chemotherapy with or without postoperative radiation.
OS served as the primary endpoint. The rate of serious adverse events, defined as any event that required hospital admission between 2 and 6 months after surgery, served as a secondary endpoint.
The mean follow-up was 54 months (95% CI, 51-56).
The majority of patients (84%) underwent surgery alone, whereas 9% underwent chemotherapy following a lobectomy, and 7% underwent postoperative radiation treatment with or without adjuvant chemotherapy.
Patients treated with adjuvant chemotherapy tended to be younger (P < .0001) and were more likely to have been diagnosed after 2005 (P < .0001). Patients with the most complications after surgery (P = .01) and a longer hospital stay after surgery (P = .01) were less likely to receive adjuvant care.
Those who received postoperative radiation therapy were more likely to have been diagnosed pre-2000 (P < .0001) and have a less comorbidity burden (P = .0001).
Using Cox regression analysis, the investigators determined that adjuvant chemotherapy was associated with longer OS (HR = 0.82; 95% CI, 0.68-0.98). However, receipt of postoperative radiation therapy — regardless of receipt of adjuvant chemotherapy — was associated with shorter OS (HR = 1.91; 95% CI, 1.64-2.23) compared with surgery alone.
When researchers stratified the results by age, adjuvant chemotherapy was associated with improved survival among patients aged 75 years or younger (HR = 0.73; 95% CI, 0.64-1.23) but not among patients aged at least 76 years (HR = 0.88; 95% CI, 0.64-1.23).
Serious adverse events occurred in 10.3% of patients who underwent surgery alone, 20.9% of patients who received adjuvant chemotherapy, and 30.8% of patients who received postoperative radiation with or without adjuvant chemotherapy.
The most common serious adverse events among patients who received adjuvant chemotherapy were anemia (6.3%) and dehydration (5.3%).
Patients who received adjuvant chemotherapy were more likely to be hospitalized for neutropenia (OR = 21.2; 95% CI, 5.8-76.6) or dehydration (OR = 3.4; 95% CI, 1.8-6.4) than patients who underwent surgery alone.
Patients who underwent postoperative radiation with or without adjuvant chemotherapy were at greater risk for hospitalization due to thrombocytopenia (OR = 14.6; 95% CI, 2.9-74.2), esophagitis (OR = 8.5; 95% CI, 2.7-26.7), pneumonitis (OR = 6.1; 95% CI, 3.3-11.3), dehydration (OR = 4.4, 95% CI, 2.3-8.4) or anemia (OR = 2.6; 95% CI, 1.5-4.5).
Patients who underwent postoperative radiation also were more likely to experience at least one adverse event (OR = 3.8; 95% CI, 2.6-5.5).
“Our study results suggest that adjuvant chemotherapy is associated with improved overall survival in patients aged 65 and older who underwent lobectomy for T2N0 NSCLC [tumors at least 4 cm],” Malhotra and colleagues concluded. “Physicians should discuss the potential benefits and risks of adjuvant chemotherapy with their elderly patients with early-stage lung cancer.” – by Anthony SanFilippo
Disclosure: The researchers report no relevant financial disclosures.