|LETTER TO EDITOR
|Year : 2020 | Volume
| Issue : 2 | Page : 383-385
Authors' reply to Vora et al. and Singh et al.
Akhil Kapoor1, Vanita Noronha1, Vijay M Patil1, Amit Joshi1, Nandini Menon1, Anuradha Chougule1, Pratik Chandrani1, Vaishakhi Trivedi1, Vichitra Behel1, Rajiv Kumar2, Abhishek Mahajan3, Amit Janu3, Kumar Prabhash1
1 Department of Medical Oncology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India
2 Department of Pathology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India
3 Department of Radiodiagnosis, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra, India
|Date of Submission||08-Apr-2020|
|Date of Decision||12-Apr-2020|
|Date of Acceptance||20-Apr-2020|
|Date of Web Publication||19-Jun-2020|
Department of Medical Oncology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kapoor A, Noronha V, Patil VM, Joshi A, Menon N, Chougule A, Chandrani P, Trivedi V, Behel V, Kumar R, Mahajan A, Janu A, Prabhash K. Authors' reply to Vora et al. and Singh et al. Cancer Res Stat Treat 2020;3:383-5
|How to cite this URL:|
Kapoor A, Noronha V, Patil VM, Joshi A, Menon N, Chougule A, Chandrani P, Trivedi V, Behel V, Kumar R, Mahajan A, Janu A, Prabhash K. Authors' reply to Vora et al. and Singh et al. Cancer Res Stat Treat [serial online] 2020 [cited 2020 Jul 9];3:383-5. Available from: http://www.crstonline.com/text.asp?2020/3/2/383/287208
We thank Vora and Nikita  for their interest in our article  and the accompanying editorial  and providing constructive comments. We performed additional analyses as suggested and report the results in this letter. The survival of patients aged ≤50 years (younger patients) was compared with that of ≥60 years (older patients) by the Kaplan–Meier  and Cox regression analysis., The median progression-free survival (PFS) of younger patients (n = 219) was 8.2 months (95% confidence interval [CI], 7.6–8.8) versus 10 months (95% CI, 7.8–12.1) for older patients (n = 199) (P = 0.829). The median overall survival (OS) of younger patients was 23.4 months (95% CI, 18.9–27.8) versus 19.4 months (95% CI, 14.4–24.4) for older patients (Hazard ratio [HR], 1.4; 95% CI, 1.0–1.8, P = 0.034), [Figure 1]. It should be noted that this result is contrary to that reported by Wu et al. in which the shortest median PFS occurred in patients aged ≤50 years (7.3 months), followed by those aged 51–60 years (8.7 months), >80 years (8.8 months), 61–70 years (9.6 months), and 71–80 years (10.1 months) (P = 0.033). Similarly, the study by Kato et al. reported young age to be a predictor of low osimertinib efficacy in both univariate and multivariate analysis in patients with acquired T790M-mutated non-small cell lung cancer patients. The difference in results can be ascribed to the differences in the type of epidermal growth factor receptor (EGFR) mutations in the studies. In the study by Wu et al., more uncommon EGFR mutations were found in younger patients (22.2% vs. 10.2%; P = 0.009) than in patients aged >50 years. In our study, non-exon 19 EGFR mutations were found in 44% (79/219) of younger patients as compared to 55% (99/199) of older patients (Pearson Chi-square test; P = 0.005). Thus, non-exon 19 EGFR mutation was found to be significantly higher in older patients in our study which might explain the poorer outcomes in older patients.
|Figure 1: Kaplan–Meier survival curve of younger (≤50 years) versus older (≥60 years) patients|
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We performed a univariate and multivariate analysis by Cox regression method for both PFS and OS in older patients. Smoking status and treatment arm were significantly related to PFS. The patients who received gefitinib had significantly better PFS (HR, 0.3, 95% CI, 0.2–0.6, P < 0.001) as compared to chemotherapy. Similarly, patients receiving gefitinib plus chemotherapy (GC) had better PFS (HR, 0.2, 95% CI, 0.1–0.4, P < 0.001) as compared to chemotherapy alone. When older patients receiving GC were compared with those receiving gefitinib alone, the PFS was significantly better in patients receiving GC (median PFS, 16 months [95% CI, 10.6–21.3] versus 9 months [95% CI, 6.6–11.4]; HR, 1.7; 95% CI, 1.1–2.7, P = 0.012), [Table 1]. The difference in OS was significant in the univariate analysis for gender, smoking status, and the mutation type of EGFR; however, none of them were noted to be significant in the multivariate analysis [Table 2].
|Table 1: Univariate and multivariate analysis of progression free survival for older patients (≥60 years)|
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|Table 2: Univariate and multivariate analysis of overall survival for older patients (≥60 years)|
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We thank Singh et al. for their comments and for pointing out the plausible explanation of the effect of smoking on the OS of older patients. In our study, we specifically found that OS in older patients who were smokers was lower than that of younger patients. Cumulatively, more tobacco exposure is expected to occur in older patients as compared to their younger counterparts because of the relatively late diagnosis and smoking cessation. This is in agreement with Wu et al. who reported that current smokers had the shortest PFS (6.9 months) for EGFR-directed therapy when compared with patients who were never-smokers (9.1 months) and ex-smokers (9.4 months) (P = 0.015). Another important issue that has been highlighted by Singh et al. is the impact of drug interactions in older patients with multiple comorbidities. This information was not available in our database, and hence, could not be analyzed. However, it should be noted that we discourage the use of proton-pump inhibitors and H2 blockers in all our patients to avoid the possible interactions. Whenever patients need to take medications for dyspepsia, we advise the use of antacids and ask them to space it from the time of taking tyrosine kinase inhibitors by at least 6 hours.
We would again like to highlight that merely considering numerical age as an exclusion criterion for aggressive treatments should not be the norm and older patients should also be enrolled in future randomized trials so that we can generate more data and can answer more questions with certainty.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]