"Major pathologic response" in lymph nodes: a modified nodal classification for non-small cell lung cancer patients treated with neoadjuvant immunochemotherapy

"Percentage" and "size" of residual viable tumor in lymph node, the performance in estimating pathologic response of lymph node in non-small cell lung cancer treated with neoadjuvant chemoimmunotherapy

There is no universally accepted method for evaluating lymph node metastasis (LNM) in non-small cell lung cancer (NSCLC) after neoadjuvant chemoimmunotherapy. Different protocols recommend evaluating the percentage of residual viable tumor (RVT%) and metastatic tumor size (MTS). Our aim was to determine the prognostic significance of RVT% and MTS, and identify the more effective parameter for pathological evaluating LNM. Two independent cohorts were collected (derivation, n = 84; external validation, n = 42). All patients exhibited metastatic cancer or treatment response in lymph nodes post-surgery. In the derivation cohort, we assessed the mean and largest values of MTS and RVT% in LNM, estimating their optimal cutoffs for event-free survival (EFS) using maximally selected rank statistics. Validation was subsequently conducted in the external validation cohort. The quality of prognostic factors was evaluated using the Area Under Curve (AUC). A positive association was identified between RVT% and MTS, but an absolute association could not be conclusively established. In the derivation cohort, neither the largest MTS (cutoff = 6 mm, p = 0.28), largest RVT% (cutoff = 75%, p = 0.23), nor mean RVT% (cutoff = 55%, p = 0.06) were associated with EFS. However, mean MTS (cutoff = 4.5 mm) in lymph nodes was statistically associated with EFS (p = 0.018), validated by the external cohort (p = 0.017). The prognostic value of MTS exceeded that of ypN staging in both cohorts, as evidenced by higher AUC values. The mean value of MTS can effectively serve as a parameter for the pathological evaluation of lymph nodes, with a threshold of 4.5 mm, closely linked to EFS. Its prognostic value outperforms that of ypN staging.

Video-Assisted Thoracoscopic Surgery Versus Thoracotomy Following Neoadjuvant Immunochemotherapy in Resectable Stage III Non-Small Cell Lung Cancer Among Chinese Populations: A Multi-Center Retrospective Cohort Study

BACKGROUND

Immune checkpoint inhibitors have revolutionized non-small cell lung cancer (NSCLC) treatment but may pose greater technical challenges for surgery. This study aims to assess the feasibility and oncological effectiveness of video-assisted thoracoscopic surgery (VATS) for resectable stage III NSCLC after neoadjuvant immunochemotherapy.

METHODS

Initial stage IIIA-IIIB NSCLC patients with neoadjuvant immunochemotherapy undergoing either VATS or open lobectomy at 6 medical centers during 2019-2023 were retrospectively identified. Perioperative outcomes and 2-year survival was analyzed. Propensity-score matching (PSM) was employed to balance patient baseline characteristics.

RESULTS

Among the total 143 patients, PSM yielded 62 cases each for VATS and OPEN groups. Induction-related adverse events were comparable between the 2 groups. VATS showed a 14.5% conversion rate. Notably, VATS decreased numeric rating scales for postoperative pain, shortened chest tube duration (5[4-7] vs. 6[5-8] days, P = .021), reduced postoperative comorbidities (21.0% vs. 37.1%, P = .048), and dissected less N1 lymph nodes (5[4-6] vs. 7[5-9], P = .005) compared with thoracotomy. Even when converted, VATS achieves perioperative outcomes equivalent to thoracotomy. Additionally, over a median follow-up of 29.5 months, VATS and thoracotomy demonstrated comparable 2-year recurrence-free survival (77.20% vs. 73.73%, P = .640), overall survival (87.22% vs. 88.00%, P = .738), cumulative incidences of cancer-related death, and recurrence patterns. Subsequent subgroup comparisons and multivariate Cox analysis likewise revealed no statistical difference between VATS and thoracotomy.

CONCLUSION

VATS is a viable and effective option for resectable stage III NSCLC patients following neoadjuvant immunochemotherapy, leading to decreased surgical-related pain, earlier chest tube removal, reduced postoperative complications, and similar survival outcomes compared to thoracotomy.

Comparison of different criteria for estimating major pathological response in resectable non-small cell lung cancer treated with neoadjuvant chemoimmunotherapy

BACKGROUND

Major pathological response (MPR) is proposed as a surrogate endpoint for survival in non-small cell lung cancer (NSCLC) after neoadjuvant chemoimmunotherapy. However, the criteria for estimating MPR differ between the recommendations of the International Association for the Study of Lung Cancer (IASLC) and the immune-related pathologic response criterion (irPRC). IASLC's criteria focus solely on evaluating the primary tumor, while irPRC's criteria encompass both the primary tumor and lymph node metastasis. Our objective is to compare the prognostic value of different criteria for estimating MPR.

METHODS

We conducted a retrospective study on a cohort of 235 patients with NSCLC after neoadjuvant chemoimmunotherapy. The survival endpoint was event-free survival (EFS). The MPR status of each patient was evaluated using both IASLC's criteria and irPRC's criteria. The prognostic value was compared using the Area Under Curve (AUC).

RESULTS

The MPR rates were 63.4 % (149/235) and 57.4 % (135/235) according to IASLC's and irPRC's criteria, respectively. Inconsistent cases, characterized by MPR status according to IASLC's criteria but non-MPR status according to irPRC's criteria, constituted 6.0 % (14/235) of the overall cohort and 15.2 % (14/92) of patients with pretreatment N positive disease. Interestingly, all inconsistent patients showed no recurrence during the study period. Although both MPR statuses according to IASLC (p = 0.00039) and irPRC (p = 0.0094) were associated with improved EFS, IASLC's criteria (AUC = 0.65) were superior to irPRC's criteria (AUC = 0.62) with a higher AUC value.

CONCLUSION

IASLC's criteria for estimating MPR were superior to irPRC's criteria in predicting EFS for NSCLC after neoadjuvant chemoimmunotherapy.

Impact of lymphadenectomy extent on immunotherapy efficacy in postresectional recurred non-small cell lung cancer: a multi-institutional retrospective cohort study

BACKGROUND

Lymph node (LN) dissection is a common procedure for non-small cell lung cancer (NSCLC) to ascertain disease severity and treatment options. However, murine studies have indicated that excising tumor-draining LNs diminished immunotherapy effectiveness, though its applicability to clinical patients remains uncertain. Hence, the authors aim to illustrate the immunological implications of LN dissection by analyzing the impact of dissected LN (DLN) count on immunotherapy efficacy, and to propose a novel 'immunotherapy-driven' LN dissection strategy.

MATERIALS AND METHODS

The authors conducted a retrospective analysis of NSCLC patients underwent anti-PD-1 immunotherapy for recurrence between 2018 and 2020, assessing outcomes based on DLN count stratification.

RESULTS

A total of 144 patients were included, of whom 59 had a DLN count less than or equal to 16 (median, IQR: 11, 7-13); 66 had a DLN count greater than 16 (median, IQR: 23, 19-29). With a median follow-up time of 14.3 months (95% CI: 11.0-17.6), the overall median progression-free survival (PFS) was 7.9 (95% CI: 4.1-11.7) months, 11.7 (95% CI: 7.9-15.6) months in the combination therapy subgroup, and 4.8 (95% CI: 3.1-6.4) months in the immunotherapy alone subgroup, respectively. In multivariable Cox analysis, DLN count less than or equal to 16 is associated with an improved PFS in all cohorts [primary cohort: HR=0.26 (95% CI: 0.07-0.89), P =0.03]; [validation cohort: HR=0.46 (95% CI: 0.22-0.96), P =0.04]; [entire cohort: HR=0.53 (95% CI: 0.32-0.89), P =0.02]. The prognostic benefit of DLN count less than or equal to 16 was more significant in immunotherapy alone, no adjuvant treatment, pN1, female, and squamous carcinoma subgroups. A higher level of CD8+ central memory T cell (Tcm) within LNs was associated with improved PFS (HR: 0.235, 95% CI: 0.065-0.845, P =0.027).

CONCLUSIONS

An elevated DLN count (cutoff: 16) was associated with poorer immunotherapy efficacy in recurrent NSCLC, especially pronounced in the immunotherapy alone subgroup. CD8+Tcm proportions in LNs may also impact immunotherapy efficacy. Therefore, for patients planned for adjuvant immunotherapy, a precise rather than expanded lymphadenectomy strategy to preserve immune-depending LNs is recommended.