Cancer antigen profiling for malignant pleural mesothelioma immunotherapy: expression and coexpression of mesothelin, cancer antigen 125, and Wilms tumor 1

Background

To develop cancer antigen-targeted immunotherapeutic strategies for malignant pleural mesothelioma (MPM), we investigated the individual and coexpressions of the cancer-associated antigens mesothelin (MSLN), cancer antigen 125 (CA125), and Wilms tumor 1 (WT1) in both epithelioid and non-epithelioid MPM.

Methods

All available hematoxylin and eosin-stained slides from patients who were diagnosed with MPM (1989-2010) were reviewed. We constructed tissue microarrays from 283 patients (epithelioid = 234; non-epithelioid = 49). Intensity and distribution for each antigen were assessed by immunohistochemistry.

Results

Positive expression of MSLN, CA125, and WT1 were demonstrated in 93%, 75%, and 97% of epithelioid MPM cases, and 57%, 33%, and 98% of non-epithelioid MPM cases, respectively. Triple- and double-positive antigen coexpressions were demonstrated in 72% and 23% of epithelioid MPM cases and 29% and 33% of non-epithelioid MPM cases, respectively. Complete absence of expression for all three antigens was demonstrated in <2% of MPM cases. More than two-thirds of MPM cases had ≥50% distribution of MSLN-positive cells and, among the remaining third, half had ≥50% distribution of WT1-positive cells. CA125/MSLN coexpression was observed in more than two-thirds of epithelioid MPM cases and one-third of non-epithelioid MPM cases.

Conclusion

A limited number of cancer-associated antigens can target almost all MPM tumors for immunotherapy.

Spread through Air Spaces (STAS) Is an Independent Predictor of Recurrence and Lung Cancer-Specific Death in Squamous Cell Carcinoma

INTRODUCTION

Spread through air spaces (STAS) is a recently recognized pattern of invasion in lung adenocarcinoma; however, it has not yet been characterized in squamous cell carcinoma (SCC).

METHODS

We reviewed 445 resected stage I to III lung SCCs and investigated the clinical significance of STAS. Cumulative incidence of recurrence and lung cancer-specific death were evaluated by competing risks analyses and overall survival by Cox models.

RESULTS

Of the total 445 patients, 336 (76%) were older than 65 years. Among the 273 patients who died, 91 (33%) died of lung cancer whereas the remaining ones died of competing events or unknown cause. STAS was observed in 132 patients (30%) and the frequency increased with stage. The cumulative incidences of any, distant, and locoregional recurrence as well as lung cancer-specific death were significantly higher in patients with STAS compared with in those without STAS, whereas there was no statistically significant difference in overall survival. In multivariable models for any recurrence and lung cancer-specific death, STAS was an independent predictor for both outcomes (p = 0.034 and 0.016, respectively).

CONCLUSION

STAS was present in one-third of resected lung SCCs. In competing risks analysis in a cohort in which three-fourths of the patients were elderly, STAS was associated with lung cancer-specific outcomes. Our findings suggest that STAS is one of the most prognostically significant histologic findings in lung SCC.

Impact of Increasing Age on Cause-Specific Mortality and Morbidity in Patients With Stage I Non-Small-Cell Lung Cancer: A Competing Risks Analysis

Purpose To perform competing risks analysis and determine short- and long-term cancer- and noncancer-specific mortality and morbidity in patients who had undergone resection for stage I non-small-cell lung cancer (NSCLC). Patients and Methods Of 5,371 consecutive patients who had undergone curative-intent resection of primary lung cancer at our institution (2000 to 2011), 2,186 with pathologic stage I NSCLC were included in the analysis. All preoperative clinical variables known to affect outcomes were included in the analysis, specifically, Charlson comorbidity index, predicted postoperative (ppo) diffusing capacity of the lung for carbon monoxide, and ppo forced expiratory volume in 1 second. Cause-specific mortality analysis was performed with competing risks analysis. Results Of 2,186 patients, 1,532 (70.1%) were ≥ 65 years of age, including 638 (29.2%) ≥ 75 years of age. In patients < 65, 65 to 74, and ≥ 75 years of age, 5-year lung cancer-specific cumulative incidence of death (CID) was 7.5%, 10.7%, and 13.2%, respectively (overall, 10.4%); noncancer-specific CID was 1.8%, 4.9%, and 9.0%, respectively (overall, 5.3%). In patients ≥ 65 years of age, for up to 2.5 years after resection, noncancer-specific CID was higher than lung cancer-specific CID; the higher noncancer-specific, early-phase mortality was enhanced in patients ≥ 75 years of age than in those 65 to 74 years of age. Multivariable analysis showed that low ppo diffusing capacity of lung for carbon monoxide was an independent predictor of severe morbidity ( P < .001), 1-year mortality ( P < .001), and noncancer-specific mortality ( P < .001), whereas low ppo forced expiratory volume in 1 second was an independent predictor of lung cancer-specific mortality ( P = .002). Conclusion In patients who undergo curative-intent resection of stage I NSCLC, noncancer-specific mortality is a significant competing event, with an increasing impact as patient age increases.