Factor associated with failure to administer subsequent treatment after progression in the first-line chemotherapy in EGFR-mutant non-small cell lung cancer: Okayama Lung Cancer Study Group experience

First and repeat rebiopsy for detecting EGFR T790M mutation in non-small-cell lung cancer: CS-Lung-003 prospective observational registry study

PURPOSE

Osimertinib is still essential for the treatment of epidermal growth factor receptor (EGFR)-T790M-positive non-small-cell lung cancer (NSCLC) even in a relapsed setting, which suggests the importance of rebiopsy. The clinical value of repeat rebiopsy in patients with NSCLC who are T790M-negative on a first rebiopsy remains unclear. In this study, we examined the status of the first rebiopsy and evaluated the frequency of repeat rebiopsy of T790M-negative tumors detected by the first rebiopsy.

METHODS

We reviewed 144 patients with NSCLC with major EGFR mutations, but not T790M, who received first- or second-generation EGFR tyrosine kinase inhibitors (TKIs), registered in the prospective, umbrella-type lung cancer patient registry (CS-Lung-003).

RESULTS

Overall, 63 patients (44%) underwent the first rebiopsy. In the first rebiopsy, 51 (81%) and 12 (19%) of 63 underwent histological/cytological rebiopsy and liquid biopsy with the blood sampling, respectively. In the repeat rebiopsy, 23 (85%) and 4 (15%) of 27 underwent histological/cytological rebiopsy and liquid biopsy, respectively. The most frequently rebiopsied site was a pulmonary lesion (n = 24, 38.7%). Overall, 29 (46.0%) of 63 patients harbored the T790M mutation. Interestingly, a high detection rate of cancer cells did not necessarily indicate a high detection rate of the T790M mutation (p < 0.01). Among 34 patients with T790M-negative tumors confirmed on the first rebiopsy, 20 (58.8%) underwent repeat rebiopsies following interval therapy, revealing that seven (36.8%) had T790M-positive tumors. Osimertinib yielded median progression-free survival of 11.8 and 16.2 months in patients with the 790M mutation detected by the first rebiopsy and repeat rebiopsy, respectively.

CONCLUSION

In our prospective cohort, the T790M mutation was detected in 46% of patients who underwent the first rebiopsy. Repeat rebiopsy may increase the ability to detect the T790M mutation positivity rate.

Number of metastatic organs negatively affects the treatment sequence in patients with EGFR-TKI failure

Background

Several studies have previously demonstrated the survival benefit of both EGFR‐TKI treatment and chemotherapy in patients with non‐small cell lung cancer (NSCLC) harboring EGFR mutations. The aim of the present study was to clarify the factors influencing the treatment sequence after failure of EGFR‐TKI therapy, focusing on the number of organs with metastasis (hereafter, metastatic organs).

Methods

Between January 2010 and December 2016, consecutive patients with EGFR‐mutated NSCLC who were started on first‐line EGFR‐TKI were reviewed. The factors influencing withholding systemic chemotherapy and the post‐progression survival (PPS) after failure of EGFR‐TKI were investigated.

Results

A total of 393 patients were started on first‐line EGFR‐TKI during the study period. After excluding patients maintained on EGFR‐TKI or who received osimertinib targeting secondary EGFR T790M, 297 patients were included in the analysis. Among these, 180 (60.6%) received chemotherapy after failure of EGFR‐TKI (TKI‐Ct group), while the remaining 117 (39.4%) received no chemotherapy (TKI‐only group). Multivariate analysis identified older age (≥75 years: odds ratio [OR] = 0.25, 95% confidence interval [CI]: 0.11–0.43, P < 0.001), poor performance status (PS) (≥2: OR = 0.06, 95% CI: 0.03–0.15, P < 0.001), and three or more metastatic organs (OR = 0.42, 95% CI: 0.22–0.80, P = 0.008) as being significantly associated with withholding of chemotherapy after failure of EGFR‐TKI.

Conclusion

A relatively large number of metastatic organs and a poor PS were associated with the withholding of subsequent chemotherapy after failure of EGFR‐TKI in EGFR‐mutated NSCLC patients. Further research for patients with such a poor prognosis should be investigated in the future.

Programmed cell death-ligand 1 expression and efficacy of cisplatin-based chemotherapy in lung cancer: A sub-analysis of data from the two Okayama Lung Cancer Study Group prospective feasibility studies

BACKGROUND

Cisplatin-based chemotherapy remains the mainstay treatment for advanced lung cancer; however, it remains controversial whether the efficacy of chemotherapy can be modulated by the immune-checkpoint status. In this study, we investigated the relationship between programmed cell death-ligand 1 (PD-L1) expression status and the efficacy of cisplatin-based chemotherapy by using individual patient data and pathological specimens obtained during our two previously performed prospective studies on the feasibility of short-term low-volume hydration in patients with advanced lung cancer who received cisplatin-based chemotherapy.

METHODS

Among 91 patients who participated in the two aforementioned trials, those with assessable tumor specimens were included in this sub-analysis. PD-L1 expression levels were determined using immunohistochemical staining, while the Response Evaluation Criteria in Solid Tumors, version 1.1, were used for determining treatment efficacy.

RESULTS

Thirty-two patients were investigated. PD-L1 expression was observed in 8 patients (25.0%; the PD-L1-positive group), with 2 exhibiting a PD-L1 expression of 50% or more. None of the patients in the PD-L1-positive group responded to treatment, while the overall response rate in the PD-L1-negative group was 20.8% (5 of 24; P = 0.296). Both the progression-free survival and overall survival rates were worse in the PD-L1-positive group than in the PD-L1-negative group (3.7 vs. 5.9 months [P = 0.018] and 5.8 vs. 37.3 months [P = 0.070], respectively).

CONCLUSION

PD-L1 expression was negatively correlated with survival in patients receiving cisplatin-based chemotherapy.

Recent trends in the treatment of unresectable stage III non-small-cell lung cancer

Approximately 20-25% of non-small-cell lung cancer (NSCLC) is diagnosed when the disease has progressed to clinical stage III. At this stage, and even if the cancer is considered unresectable, the treatment strategy should aim to achieve a cure. At the time of the initial diagnosis, it is necessary for medical oncologists to devise the best treatment strategy for each patient by composing a multidisciplinary treatment team including thoracic surgeons and radiation oncologists. In this review, we summarize prior pivotal clinical trials in unresectable clinical stage III NSCLC. Furthermore, we review very recent clinical trials evaluating the efficacy of immune checkpoint inhibitors in the treatment of NSCLC.

Recent treatment strategy for advanced squamous cell carcinoma of the lung in Japan

Squamous cell carcinoma of the lung is associated with smoking in its development and comprises about 20-30% of all lung cancers. Its treatment strategy had been limited for the past decades, inevitably resulting in the poor outcome. However in the 2010s, it has dramatically changed mainly with the recent clinical introduction of immune checkpoint inhibitors. In this review, we will introduce various clinical studies involving squamous cell carcinoma of the lung.