Prognostic impact of M descriptors of the 8th edition of TNM classification of lung cancer

Single organ metastatic sites in non-small cell lung cancer: Patient characteristics, treatment patterns and outcomes from a large retrospective Canadian cohort

BACKGROUND

There is a paucity of information about the characteristics, treatment patterns, and outcomes of non-small cell lung cancer (NSCLC) patients with single organ metastasis (SOM).

METHODS

This retrospective cohort study includes all patients with a diagnosis of stage IV NSCLC diagnosed from 2014 to 2016 and treated at Princess Margaret Cancer Centre. We compared baseline characteristics and patterns of metastatic sites between patients with SOM versus multiple (M)OM. Additionally, we identified treatment modalities and outcomes for patients with SOM. Cox multivariable models (MVA) were utilized to evaluate differences in overall survival (OS) between the SOM and MOM cohorts.

RESULTS

Of 893 pts analyzed, 457 (51 %) had SOM, while 436 (49 %) had MOM at initial diagnosis. Demographics were comparable between the two groups. Brain was the most common site of metastasis for SOM patients. When compared to the MOM group, the SOM group had lower percentages of liver and adrenal metastases. Amongst SOM patients, 54 % received single modality treatment, and 20 % did not receive any treatment for their SOM. In MVA, patients with liver (HR 2.4), bone (HR 1.8), and pleural (HR 1.7) metastasis as their SOM site had the worst outcomes, with median OS of 6.8 months, 12.1 months, and 13.0 months respectively. Patients with SOM had a significantly improved median OS compared to those with MOM (15.9 months vs. 10.6 months; HR 0.56, 95 % CI 0.47-0.66, p < 0.001).

CONCLUSION

In NSCLC patients who presented with SOM, survival correlated with the initial organ involved and was better overall compared to patients with MOM. SOM NSCLC may benefit from specific management strategies and SOM patients could be considered as a specific subgroup for survival analyses in observational and non-randomized interventional studies. In clinical trials, SOM can be considered as a stratification factor in the future.

The International Association for the Study of Lung Cancer Staging Project for Lung Cancer: Proposals for the Revision of the M Descriptors in the Forthcoming Ninth Edition of the TNM Classification for Lung Cancer

INTRODUCTION

This study analyzed all metastatic categories of the current TNM classification of NSCLC to propose modifications of the M component in the next edition (ninth) of the classification.

METHODS

A database of 124,581 patients diagnosed between 2011 and 2019 was established; of these, 14,937 with NSCLC in stages IVA to IVB were available for this analysis. Overall survival was calculated using the Kaplan-Meier method, and prognosis was assessed using multivariable-adjusted Cox proportional hazards regression.

RESULTS

The eighth edition M categories revealed good discrimination in the ninth edition data set. Assessments revealed that an increasing number of metastatic lesions were associated with decreasing prognosis; because this seems to be a continuum and adjustment for confounders was not possible, no specific lesion number was deemed appropriate for stage classification. Among tumors involving multiple metastases, decreasing prognosis was found with an increasing number of organ systems involved. Multiple assessments, including after adjustment for potential confounders, revealed that M1c patients who had metastases to a single extrathoracic organ system were prognostically distinct from M1c patients who had involvement of multiple extrathoracic organ systems.

CONCLUSIONS

These data validate the eighth edition M1a and M1b categories, which are recommended to be maintained. We propose the M1c category be divided into M1c1 (involvement of a single extrathoracic organ system) and M1c2 (involvement of multiple extrathoracic organ systems).

Future Perspectives on the TNM Staging for Lung Cancer

Since its conception by Pierre Denoix in the mid-20th century, the tumor, node, and metastasis (TNM) classification has undergone seven revisions. The North American database managed by Clifton Mountain was used to inform the 2nd to the 6th editions, and an international database collected by the International Association for the Study of Lung Cancer, promoted by Peter Goldstraw, was used to inform the 7th and the 8th editions. In these two latest editions, it was evident that the impact of tumor size was much greater than it was suggested in previous editions; that the amount of nodal disease had prognostic relevance; and that the number and location of the distant metastases had prognostic implications. However, the TNM classification is not the only prognostic factor. Data are being collected now to inform the 9th edition of the TNM classification, scheduled for publication in 2024. Patient-, environment-, and tumor-related factors, including biomarkers (genetic biomarkers, copy number alterations, and protein alterations) are being collected to combine them in prognostic groups to enhance the prognosis provided by the mere anatomic extent of the tumor, and to offer a more personalized prognosis to an individual patient. International collaboration is essential to build a large and detailed database to achieve these objectives.

New TNM staging in lung cancer (8th edition) and future perspectives

BACKGROUND

Carrying out a correct anatomical classification of lung cancer is crucial to take clinical and therapeutic decisions in each patient.

AIM

TNM staging classification provides an accurate anatomical description about the extension of the disease; however, the anatomical burden of the disease is just one aspect that changes the prognosis.

RELEVANCE FOR PATIENTS

TNM staging classification is a tool that predicts survival, but we must consider that TNM is just one of the factors that concern the prognosis. The impact of a factor over the prognosis is complex due to: It depends on the specific environment, the treatment strategy, among others, and our level of certainty makes difficult to include all the factors just in a group of stages. In some groups, there are difficulties to get large series due to the low frequency of cases and the small number of events (metastasis, locoregional recurrence). It does not allow to obtain evidence in a short period of time. On the other hand, in the next years, new markers will be incorporated in the coming years, which are going to be included in the new TNM classification. It could help to improve the classification giving more information about prognosis and risk of recurrence. All these aspects are being used by the International Association for the Study of Lung Cancer (IASLC) to develop a new prognosis model. This continues the evolution of TNM system, allows us to overcome the difficulties, and build a flexible framework enough to continue improving the individual prognosis of the patients.

Extracranial Stereotactic Body Radiotherapy in Oligometastatic or Oligoprogressive Breast Cancer

Purpose/Objective: Oligometastatic disease (OMD) and oligoprogressive disease (OPD) describe tumor states with a limited metastasization. In contrast to other disease states, treatment of OMD or OPD has not yet become common for breast cancer. We sought to understand the outcomes and toxicities of this treatment paradigm. Material/Methods: We retrospectively analyzed female breast cancer patients with OMD (≤3 metastases) or OPD (1 progressive lesion) who received stereotactic body radiotherapy (SBRT) for their respective extracranial metastatic lesions between 01/2002 and 07/2019. Survival analysis was performed using the Kaplan-Meier method with log-rank test being used for evaluation of significance. Cox regression was used to detect prognostic outcome factors. Toxicity was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE v. 5.0). Results: Forty-six patients (70% OMD; 30% OPD) with 58 lesions met criteria for inclusion. The majority of treatments (34 out of 58; 58.6%) were delivered from 2017 to 2018. Treatment sites were bone, liver, lung [n = 19 (33%) for each site], and adrenal gland [n = 1 (1%)]. Median biologically effective dose (BED at α/β = 10) was 81.6 Gy (range: 45-112.5 Gy) and median planning target volume was 36.60 mL (range: 3.76-311.00 mL). At 2 years, local control (LC) was 89%, distant control (DC) was 44%, progression free survival (PFS) was 17% and overall survival (OS) was 62%. Multivariate analysis identified the diagnosis of a solitary metastasis as an independent prognostic factor for superior DC (HR = 0.186, CI [0.055; 0.626], p = 0.007) and PFS (HR = 0.363, CI [0.152; 0.863], p = 0.022). OS was independently inferior for patients treated at a higher age (HR = 5.788, CI [1.077; 31.119] p = 0.041). Nine (15.5%) grade I° and one (1.7%) grade II° toxicities were recorded, with no grade III° or higher toxicities. Conclusion: Extracranial SBRT in breast cancer patients with OMD or OPD was well-tolerated with excellent LC. SBRT should especially be offered to younger OMD and OPD breast cancer patients with only one metastasis. The increase in utilization since 2017 points toward a growing acceptance of SBRT for OMD and OPD in breast cancer.

Association of specific metastatic organs with the prognosis and chemotherapeutic response in patients with advanced lung cancer

BACKGROUND

This study was performed to investigate the influence of specific metastatic organs on the prognosis and therapeutic effect in patients with advanced lung cancer.

METHODS

We retrospectively analyzed 400 patients with pathologically diagnosed advanced lung cancer to determine the association of the patients' metastatic status with their prognoses and responses to first-line therapy. Metastases within the chest cavity (pulmonary metastasis, pleural effusion, and pericardial effusion) were counted as one organ.

RESULTS

The numbers of metastatic organs in the patients were as follows: one (n=199 patients), two (n=99), three (n=61), and four or more (n=41). A multivariate analysis showed that liver and muscle metastases were independently associated with shorter overall survival (median of 207 and 120 days, respectively) and shorter progression-free survival (median of 125 and 53 days, respectively). Chest cavity, bone, brain, and lymph node metastases were not associated with survival. The presence of either muscle or skin metastasis was associated with a lower response rate to first-line therapy than was the absence of each metastasis (14.3% vs. 49.4% and 11.1% vs. 48.9% in patients with vs. without muscle or skin metastasis, respectively).

CONCLUSIONS

Muscle and liver metastases were associated with poor outcomes. Muscle and skin metastases were associated with a lower response rate to treatment. For patients with advanced lung cancer, oncologists should select treatment strategies considering the patients' metastatic statuses as well as other clinical characteristics.

Exosome-based detection of activating and resistance EGFR mutations from plasma of non-small cell lung cancer patients

Non-small cell lung cancer (NSCLC) is the most prevalent form of lung cancer and its molecular landscape has been extensively studied. The most common genetic alterations in NSCLC are mutations within the epidermal growth factor receptor (EGFR) gene, with frequencies between 10-40%. There are several molecular targeted therapies for patients harboring these mutations.

Liquid biopsies constitute a flexible approach to monitor these mutations in real time as opposed to tissue biopsies that represent a single snap-shot in time. However, interrogating cell free DNA (cfDNA) has inherent biological limitations, especially at early or localized disease stages, where there is not enough tumor material released into the patient’s circulation.

We developed a qPCR- based test (ExoDx EGFR) that interrogates mutations within EGFR using Exosomal RNA/DNA and cfDNA (ExoNA) derived from plasma in a cohort of 110 NSCLC patients.

The performance of the assay yielded an overall sensitivity of 90% for L858R, 83% for T790M and 73% for exon 19 indels with specificities of 100%, 100%, and 96% respectively. In a subcohort of patients with extrathoracic disease (M1b and MX) the sensitivities were 92% (L858R), 95% (T790M), and 86% (exon 19 indels) with specificity of 100%, 100% and 94% respectively.

Monitoring blood biomarkers to predict nivolumab effectiveness in NSCLC patients

Background

We investigated whether early dynamic changes of circulating free (cfDNA) levels as well as the neutrophil to lymphocyte ratio (NLR) could predict nivolumab effectiveness in pretreated patients with advanced non-small cell lung cancer (NSCLC).

Methods

A total of 45 patients receiving nivolumab 3 mg/kg every 2 weeks were enrolled. Patients underwent a computed tomography scan and responses were evaluated by the response evaluation criteria in solid tumors. Peripheral blood samples were obtained from the patients and the cfDNA level as well as the NLR were assessed. Time to progression (TTP) and overall survival (OS) were determined.

Results

Patients with increased cfDNA >20% at the sixth week reported significantly worse survival outcomes (median OS: 5.7 versus 14.2 months, p < 0.001; median TTP: 3.3 versus 10.2 months, p < 0.001), as well as patients with increased NLR >20% (median OS: 8.7 versus 14.6 months, p = 0.035; median TTP: 5.2 versus 10.3 months, p = 0.039). The combined increase of cfDNA and NLR >20% was associated with significantly worse survival outcomes as compared with the remained population (median OS: 5.8 versus 15.5 months, p = 0.012; median TTP: 3.2 versus 11.9 months, p = 0.028). Multivariable analysis identified three significant factors associated with worse OS: combined cfDNA/NLR increase >20% [hazard ratio (HR): 5.16; 95% confidence interval (CI), 1.09-24.29; p = 0.038], liver metastasis (HR: 0.44; 95% CI, 0.20-0.96; p = 0.038), and extra-thoracic disease (HR: 0.33; 95% CI, 0.12-0.89; p = 0.029).

Conclusion

An early combined increase of both cfDNA and NLR over the course of the first 6 weeks of nivolumab therapy predicted worse survival in pretreated patients with advanced NSCLC, suggesting a potential role in the real-time monitoring of immunotherapy resistance.

M1b Disease in the 8th Edition of TNM Staging of Lung Cancer: Pattern of Single Extrathoracic Metastasis and Clinical Outcome

The 8th edition of TNM staging of lung cancer revised M staging and defined M1b disease with single extrathoracic metastasis, to be distinguished from M1c with multiple extrathoracic metastases in one or more organs. This new distinct category of M1b disease consists of patients with a single extrathoracic metastasis, thus consisting of a strictly defined oligometastatic disease. This article reports the prevalence of M1b disease among patients with stage IV non‐small cell lung cancer, focusing on the clinical characteristics and patterns of single extrathoracic metastasis and relationships with overall survival.

Background.

The 8th edition of TNM staging of non‐small cell lung cancer (NSCLC) has revised M classification and defined M1b disease with single extrathoracic metastasis, which is distinguished from M1c with multiple extrathoracic metastases. We investigated the prevalence, characteristics, and overall survival (OS) of M1b disease in patients with stage IV NSCLC.

Methods.

The study reviewed the medical records and imaging studies of 567 patients with stage IV NSCLC to determine M stage using the 8th edition of TNM staging. Clinical characteristics and OS were compared according to M stages.

Results.

Among 567 patients, 57 patients (10%) had M1b disease, whereas 119 patients (21%) had M1a disease and 391 patients (69%) had M1c disease. Squamous histology was more common in M1b (16%) than in M1a (6%) and M1c (6%; p = .03). The median OS of patients with M1b disease was 14.8 months, compared with 22.6 months for patients with M1a and 13.4 months for those with M1c disease (p < .0001). Significant OS differences of M1b compared with single‐organ M1c and multiorgan M1c groups were noted (single‐organ M1c vs. M1b: hazard ratio [HR], 1.49; p = .02; multiorgan M1c vs. M1b: HR, 1.57; p = .01) in multivariable analyses adjusting for smoking and systemic therapy types. Among patients with M1b disease, the brain was the most common site of single metastasis (28/57; 49%), followed by bone (16/57; 28%). Single brain metastasis was more frequently treated with local treatment (p < .0001).

Conclusion.

M1b disease was noted in 10% of patients with stage IV NSCLC. Squamous histology was more common in M1b group than others. The brain was the most common site of single metastasis and was often treated locally.

Implications for Practice.

The newly defined group of M stage consists of a unique subset among patients with stage IV non‐small cell lung cancer that can be studied further to optimize treatment approaches.

Clinical implications of the innovations in the primary tumour and metastasis of the 8th edition of the TNM classification for lung cancer

The 8th edition of the tumour, node and metastasis (TNM) classification for lung cancer introduced two new categories to accommodate adenocarcinoma in situ (AIS)-Tis(AIS)-and minimally invasive adenocarcinoma-T1mi; subdivided T1 into T1a (≤1 cm), T1b (>1-2 cm) and T1c (>2-3 cm); and T2 into T2a (>3-4 cm) and T2b (>4-5 cm); reclassified tumours >5-7 cm as T3, and those >7 cm as T4; reclassified endobronchial location <2 cm from the carina and total atelectasis/pneumonitis as T2a; and reclassified invasion of the diaphragm as T4. Regarding metastasis, the 7^th edition M1a category remained the same, but M1b is now redefined to include single extrathoracic metastasis; and a new category, M1c, has been created for multiple extrathoracic metastases in one or in several organs. Tumours with worse prognosis than that assigned in previous editions, such as T3-4N2M0 and T3-4N3M0, were grouped in stages IIIB and IIIC, respectively. Stage IV was subdivided into IVA, for intrathoracic and single extrathoracic metastasis (M1a and M1b, respectively) and IVB, for multiple extrathoracic metastases (M1c). From the clinical point of view, these innovations will demand a more precise registration of tumour size, a thoughtful assessment of locally advanced tumours at multidisciplinary discussions, and a thorough search of extrathoracic metastases because the number of the metastatic sites has prognostic relevance and may influence therapy.