Benefit of adjuvant chemotherapy for patients with stage IB non-small cell lung cancer: a systematic review and meta-analysis

[Selection of postoperative adjuvant therapy for patients with stage IB lung adenocarcinoma: analysis of 653 cases]

OBJECTIVE

To explore the optimal postoperative adjuvant regimens for patients with stage IB lung adenocarcinoma.

METHODS

We respectively analyzed the data of 653 patients undergoing surgery for stage IB lung adenocarcinoma in our hospital from January, 2013 to December, 2021. The 5-year disease-free survival (DFS) and overall survival (OS) rates were compared among the patients receiving postoperative adjuvant therapy with epidermal growth factor-tyrosine kinase inhibitors (EGFR-TKIs group, n=111), chemotherapy (CT group, n=108) and clinical observation (CO group, n=434).

RESULTS

In TKIs, CT, and CO groups, the 5-year DFS rates were 92.8%, 80.7%, and 81.7%, respectively, significantly higher in TKIs group than in CO group (P < 0.01). The 3-year OS rates of the 3 groups were 96.8%, 97.1%, and 91.7%, respectively. Subgroup analysis showed that in TKIs, CT, and CO groups, the 5-year DFS rates of patients with with T3-4 cmN0M0 were 92.6%, 84.0%, and 81.4%, respectively, significantly higher in TKIs group than in CO group (P < 0.05); the 5-year DFS rates of T2ViscPlN0M0 patients were 95.1%, 71.4%, and 83.5%, respectively. Multivariate COX regression analysis showed that age (P < 0.05; HR=0.631, 95% CI: 0.401-0.993), solid nodules (P < 0.01; HR=7.620, 95% CI: 3.037-19.121), micropapillary or solid component (P < 0.05; HR= 1.776, 95% CI: 1.010-3.122), lymphovascular invasion (P < 0.05; HR=2.981, 95% CI: 1.198-7.419), and adjuvant therapy (P < 0.01) were independent predictors of DFS. The most common adverse effects included rashes, paronychia, and diarrhea for TKIs and hematological suppression and gastrointestinal reactions for chemotherapy, and TKIs were associated with a higher incidence of grade 3 or above adverse effects (44.4% vs 9.0%).

CONCLUSION

Adjuvant therapy with TKIs helps improve DFS in patients with stage IB (T3-4cmN0M0) lung adenocarcinoma but not in patients with T2ViscPlN0M0. Adjuvant chemotherapy does not improve DFS or OS in patients with stage IB lung adenocarcinoma.

Meta-analysis of the efficacy of postoperative adjuvant chemotherapy for stage IB non-small cell lung cancer

BACKGROUND

Many clinical trials have shown that postoperative adjuvant chemotherapy can provide a survival benefit for patients with stage IB non-small cell lung cancer. However, whether adjuvant chemotherapy should be routinely given after surgery remains controversial. Therefore, we performed a meta-analysis to investigate the efficacy of adjuvant chemotherapy versus surgery alone for stage IB non-small cell lung cancer (NSCLC).

METHODS

Relevant retrospective studies or randomized controlled trial comparing the efficacy of postoperative adjuvant chemotherapy versus observation on the survival outcomes of NSCLC patients up to October 30, 2023 were searched in PubMed, Web of Science, EMBASE, Cochrane Library, VIP database, Wanfang database, and China National Knowledge Internet database. Patient survival data, population characteristics, and other relevant information were extracted, and data were analyzed using Review Manager 5.4. The primary endpoints included overall survival, disease-free survival, and recurrence-free survival.

RESULTS

A total of 13 randomized controlled trials or cohort studies including 19,442 patients were included. The results of the meta-analysis showed that postoperative adjuvant chemotherapy in patients with stage IB NSCLC had better overall survival (odds ratio [OR] = 1.25, 95% confidence interval [CI] 1.19-1.31, P < .00001) and disease-free survival or recurrence-free survival (OR = 1.57, 95% CI 1.3-1.9, P < .00001) compared with observation; and the 4-year survival rate of patients who received postoperative adjuvant chemotherapy was better than the observation group (OR = 1.52, 95% CI 1.05-2.18, P = .03); and the 8-year survival rate of patients receiving postoperative adjuvant chemotherapy (OR = 1.5, 95% CI 0.94-2.4, P = .09) was comparable to the observation group.

CONCLUSION

Receiving postoperative adjuvant chemotherapy improved people's survival and prolonged disease-free survival and recurrence-free survival in patients with stage IB non-small cell lung cancer compared with surgery alone.

Surgically Treated pT2aN0M0 (Stage IB) Non-Small Cell Lung Cancer: A 20-Year Single-Center Retrospective Study

Introduction The suitability of adjuvant therapy (AT) in patients with stage IB non-small cell lung cancer (NSCLC) is still under debate considering the cost-benefit ratio between improvement in survival and side effects. We retrospectively evaluated survival and incidence of recurrence in radically resected stage IB NSCLC, to determine whether AT could significantly improve prognosis. Methods Between 1998 and 2020, 4692 consecutive patients underwent lobectomy and systematic lymphadenectomy for NSCLC. Two hundred nineteen patients were pathological T2aN0M0 (>3 and ≤4 cm) NSCLC 8th TNM. None received preoperative or AT. Overall survival (OS), cancer specific survival (CSS) and the cumulative incidence of relapse were plotted and log-rank or Gray's tests were used to assess the difference in outcome between groups. Results The most frequent histology was adenocarcinoma (66.7%). Median OS was 146 months. The 5-, 10-, and 15-year OS rates were 79%, 60%, and 47%, whereas the 5-, 10-, and 15-year CSS were 88%, 85%, and 83%, respectively. OS was significantly related to age (p < 0.001) and cardiovascular comorbidities (p = 0.04), whereas number of LNs removed was an independent prognostic factor of CSS (p = 0.02). Cumulative incidence of relapse at 5-, 10-, and 15-year were 23%, 31%, and 32%, respectively, and significantly related to the number of LNs removed (p = 0.01). Patients with more than 20 LNs removed and clinical stage I had a significantly lower relapse (p = 0.02). Conclusions Excellent CSS, up to 83% at 15-year, and relatively low risk of recurrence for stage IB NSCLC (8th TNM) patients suggested that AT for those patients could be reserved only for very selected high-risk cases.

Impact of surgery and adjuvant chemotherapy on the survival of stage I lung adenocarcinoma patients with tumor spread through air spaces

OBJECTIVES

Tumor spread through air spaces (STAS) is a unique mechanism of lung cancer metastasis; however, its clinical value for stage I lung adenocarcinoma (ADC) remains unclear at present. We investigated the (1) prognosis of patients after sublobar resection compared with lobectomy for stage I lung adenocarcinoma with STAS; and (2) potential benefits of adjuvant chemotherapy (ACT) for patients with stage I ADC and STAS.

METHODS

A total of 3328 consecutive patients with stage I ADC were retrospectively identified between 2014 and 2018 at our institution; among them, 600 were diagnosed with STAS. Kaplan-Meier analysis and Cox proportional hazard regression models were used to evaluate the impact of STAS on overall survival (OS) and recurrence-free survival (RFS).

RESULTS

Among stage IA patients with STAS, there was no significant difference between those who underwent sublobar resection and lobectomy in OS (P = 0.919) and RFS (P = 0.066). Multivariate analysis confirmed this result (sublobar resection versus lobectomy, OS: HR = 0.523, 95 % CI, 0.056-18.458, P = 0.714; RFS, HR = 0.360, 95 % CI, 0.115-1.565, P = 0.897). ACT did not improve the prognosis of stage IA patients but did improve the RFS of stage IB patients with high-risk recurrence factors, including poorly differentiated tumors, lymphovascular invasion and visceral pleural invasion (P = 0.046).

CONCLUSIONS

Sublobar and lobectomy resection provided a comparable prognosis for stage IA ADC patients with STAS. When STAS was confirmed postoperatively, ACT should be considered for patients with stage IB with high-risk recurrence factors but not for those with stage IA disease.

Adjuvant chemotherapy compared with observation in patients with T2aN0 stage IB lung adenocarcinoma

Introduction

For patients with T2aN0 stage IB lung adenocarcinoma, benefits of adjuvant chemotherapy remain controversial. Here, we aimed to evaluate such benefits.

Methods

This retrospective cohort study was conducted on the database of the National Taiwan Cancer Registry. We analyzed patients with T2aN0 stage IB lung adenocarcinoma (re-classified by AJCC 8th edition) diagnosed during the period from January 2011 to December 2017. They were divided into two groups: (1) group 1: tumor <=3 cm with visceral pleural invasion (VPI); (2) group 2: tumor >3 cm, but <=4 cm. Overall survival (OS) and cancer specific survival (CSS) were evaluated. Risk factors for survival were determined.

Results

A total of 2,100 patients with T2aN0 stage IB lung adenocarcinoma (1,265 in group 1 and 835 in group 2) were enrolled for study. The proportions of patients receiving adjuvant chemotherapy in group 1 and 2 were 39.1% and 68.6%, respectively. Amongst group 1 patients, adjuvant chemotherapy was not an independent risk factor for OS and CSS. Amongst group 2 patients, high-grade histologic findings and receiving sublobar resection were two risk factors for poorer survival. Adjuvant chemotherapy was also associated with an OS (adjusted hazard ratio (aHR), 0.52; 95% confidence interval (CI), 0.38-0.72; P<0.001) and CSS (aHR, 0.54; 95% CI, 0.37-0.78; p=0.001) benefit regardless of the presence or absence of risk factors.

Conclusion

For patients with T2aN0 stage IB lung adenocarcinoma, adjuvant chemotherapy improved OS and CSS in those with tumors >3 cm, but <=4 cm.For patients with tumors <=3 cm with VPI, adjuvant chemotherapy had no survival benefit.