Type B Lactic Acidosis in a Patient with Mantle Cell Lymphoma.

Type B lactic acidosis is an uncommon medical emergency in which acid production overwhelms hepatic clearance. This specific etiology of lactic acidosis occurs without organ hypoperfusion and has been most commonly described in patients with hematologic malignancies but also in patients with solid tumors. The mechanism by which cancer cells switch their glucose metabolism toward increasingly anaerobic glycolytic phenotypes has been described as the "Warburg effect." Without treating the underlying malignancy, the prognosis for patients diagnosed with malignancy-related type B lactic acidosis is extremely poor. Here, we present a case of a 66-year-old male who was diagnosed with type B lactic acidosis secondary to mantle cell lymphoma. Bicarbonate drip was started to correct the lactic acidosis. The patient was also immediately treated with rituximab chemotherapy combined with rasburicase to avoid the hyperuricemia associated with tumor lysis syndrome. He responded to the early treatment and was discharged with normal renal function. Type B lactic acidosis secondary to hematologic malignancy is important to recognize. In order to successfully treat this syndrome, early diagnosis and simultaneous treatment of the imbalance of lactic acid levels and the underlying malignancy are necessary.

Diverse EGFR Exon 20 Insertions and Co-Occurring Molecular Alterations Identified by Comprehensive Genomic Profiling of NSCLC.

INTRODUCTION: EGFR exon 20 insertions (EGFRex20ins) comprise an uncommon subset of EGFR-activating alterations relatively insensitive to first- and second-generation EGFR tyrosine kinase inhibitors (TKIs). However, recent early clinical data suggests these patients may benefit from newer-generation EGFR-TKIs. Comprehensive genomic profiling (CGP) identifies a broad spectrum of EGFRex20ins and associated co-occurring genomic alterations (GAs) present in NSCLC. METHODS: Hybrid capture-based CGP was performed prospectively on 14,483 clinically annotated consecutive NSCLC specimens to a mean coverage depth of greater than 650X for 236 or 315 cancer-related genes. RESULTS: Of 14,483 NSCLC cases, CGP identified 263 (1.8%) cases with EGFRex20ins, representing 12% (263 of 2251) of cases with EGFR mutations. Sixty-four unique EGFRex20ins were identified, most commonly D770_N771>ASVDN (21%) and N771_P772>SVDNP (20%). EGFR amplification occurred in 22% (57 of 263). The most common co-occurring GAs effected tumor protein p53 (TP53) (56%), cyclin dependent kinase inhibitor 2A (CDKN2A) (22%), cyclin dependent kinase inhibitor 2B (CDKN2B) (16%), NK2 homeobox 1 (NKX2-1) (14%) and RB transcriptional corepressor 1 (RB1) (11%); co-occurring GAs in other known lung cancer drivers were rare (5%). Average tumor mutational burden was low (mean 4.3, range 0 to 40.3 mutations/Mb). Clinical outcomes to first- and second-generation EGFR TKIs were obtained for five patients and none responded. CONCLUSIONS: In the largest series of EGFRex20ins NSCLC, diverse EGFRex20ins were detected in 12% of EGFR-mutant NSCLC, a higher frequency than previously reported in smaller single-institution studies. Clinical outcomes showed lack of response to EGFR TKIs. Tumor mutational burden was low, consistent with non-smoking associated NSCLC. Comprehensive sequencing revealed increased proportion and wide variety of EGFRex20ins, representing a population of patients significant enough for focused efforts on effective interventions.

STK11/LKB1 Mutations and PD-1 Inhibitor Resistance in KRAS-Mutant Lung Adenocarcinoma.

KRAS is the most common oncogenic driver in lung adenocarcinoma (LUAC). We previously reported that STK11/LKB1 (KL) or TP53 (KP) comutations define distinct subgroups of KRAS-mutant LUAC. Here, we examine the efficacy of PD-1 inhibitors in these subgroups. Objective response rates to PD-1 blockade differed significantly among KL (7.4%), KP (35.7%), and K-only (28.6%) subgroups (P < 0.001) in the Stand Up To Cancer (SU2C) cohort (174 patients) with KRAS-mutant LUAC and in patients treated with nivolumab in the CheckMate-057 phase III trial (0% vs. 57.1% vs. 18.2%; P = 0.047). In the SU2C cohort, KL LUAC exhibited shorter progression-free (P < 0.001) and overall (P = 0.0015) survival compared with KRASMUT;STK11/LKB1WT LUAC. Among 924 LUACs, STK11/LKB1 alterations were the only marker significantly associated with PD-L1 negativity in TMBIntermediate/High LUAC. The impact of STK11/LKB1 alterations on clinical outcomes with PD-1/PD-L1 inhibitors extended to PD-L1-positive non-small cell lung cancer. In Kras-mutant murine LUAC models, Stk11/Lkb1 loss promoted PD-1/PD-L1 inhibitor resistance, suggesting a causal role. Our results identify STK11/LKB1 alterations as a major driver of primary resistance to PD-1 blockade in KRAS-mutant LUAC.Significance: This work identifies STK11/LKB1 alterations as the most prevalent genomic driver of primary resistance to PD-1 axis inhibitors in KRAS-mutant lung adenocarcinoma. Genomic profiling may enhance the predictive utility of PD-L1 expression and tumor mutation burden and facilitate establishment of personalized combination immunotherapy approaches for genomically defined LUAC subsets. Cancer Discov; 8(7); 822-35. ©2018 AACR.See related commentary by Etxeberria et al., p. 794This article is highlighted in the In This Issue feature, p. 781.

Patient-reported predictors of early treatment discontinuation: treatment-related symptoms and health-related quality of life among postmenopausal women with primary breast cancer randomized to anastrozole or exemestane on NCIC Clinical Trials Group (CCTG) MA.27 (E1Z03).

PURPOSE: Aromatase inhibitors are the most commonly prescribed adjuvant endocrine therapy for hormone-dependent early breast cancer in postmenopausal women. Among Canadian Cancer Trials Group MA.27 participants, anastrozole and exemestane had comparable 5-year event-free survival. This companion study examined differences in patient-reported treatment-related symptoms (TRS) and health-related quality of life (HRQL) among postmenopausal women randomized to anastrozole or exemestane. METHODS: MA.27 participants (N = 686, of 7576) randomized to 5 years of anastrozole (1 mg/day, n = 371, Arm A) or exemestane (25 mg/day, n = 315, Arm E) completed the 56-item Functional Assessment of Cancer Therapy-Endocrine Symptoms (FACT-ES) questionnaire to assess TRS and HRQL. The FACT-ES was completed at baseline, 3, 6, 12, and 24 months. RESULTS: No significant differences in FACT-ES median scores measuring TRS and HRQL were observed between treatment arms at any time point. Change in TRS from baseline was statistically significant at 3, 6, 12, and 24 months. HRQL was stable over time in both arms. Greater TRS burden was associated with poorer HRQL (coefficient = 0.57, p < 0.001). Twenty percent of patients discontinued AI therapy by month 24 and 32% discontinued AIs at 4 years. In both arms, patients reporting more side effect bother prior to initiating study treatment had a higher risk of discontinuing treatment before completing protocol therapy (hazard ratio [HR] 1.29, 95% CI 1.08-1.55, p = 0.01). CONCLUSIONS: TRS and HRQL were comparable between anastrozole and exemestane. TRS negatively affect HRQL. Women who report being bothered by treatment side effects prior to initiating an AI are at increased risk for early treatment discontinuation.

Pulmonary Sarcomatoid Carcinomas Commonly Harbor Either Potentially Targetable Genomic Alterations or High Tumor Mutational Burden as Observed by Comprehensive Genomic Profiling.

INTRODUCTION: Pulmonary sarcomatoid carcinoma (PSC) is a high-grade NSCLC characterized by poor prognosis and resistance to chemotherapy. Development of targeted therapeutic strategies for PSC has been hampered because of limited and inconsistent molecular characterization. METHODS: Hybrid capture-based comprehensive genomic profiling was performed on DNA from formalin-fixed paraffin-embedded sections of 15,867 NSCLCs, including 125 PSCs (0.8%). Tumor mutational burden (TMB) was calculated from 1.11 megabases (Mb) of sequenced DNA. RESULTS: The median age of the patients with PSC was 67 years (range 32-87), 58% were male, and 78% had stage IV disease. Tumor protein p53 gene (TP53) genomic alterations (GAs) were identified in 74% of cases, which had genomics distinct from TP53 wild-type cases, and 62% featured a GA in KRAS (34%) or one of seven genes currently recommended for testing in the National Comprehensive Cancer Network NSCLC guidelines, including the following: hepatocyte growth factor receptor gene (MET) (13.6%), EGFR (8.8%), BRAF (7.2%), erb-b2 receptor tyrosine kinase 2 gene (HER2) (1.6%), and ret proto-oncogene (RET) (0.8%). MET exon 14 alterations were enriched in PSC (12%) compared with non-PSC NSCLCs (∼3%) (p < 0.0001) and were more prevalent in PSC cases with an adenocarcinoma component. The fraction of PSC with a high TMB (>20 mutations per Mb) was notably higher than in non-PSC NSCLC (20% versus 14%, p = 0.056). Of nine patients with PSC treated with targeted or immunotherapies, three had partial responses and three had stable disease. CONCLUSION: Potentially targetable GAs in National Comprehensive Cancer Network NSCLC genes (30%) or intermediate or high TMB (43%, >10 mutations per Mb) were identified in most of the PSC cases. Thus, the use of comprehensive genomic profiling in clinical care may provide important treatment options for a historically poorly characterized and difficult to treat disease.

Activation of MET via diverse exon 14 splicing alterations occurs in multiple tumor types and confers clinical sensitivity to MET inhibitors.

UNLABELLED: Focal amplification and activating point mutation of the MET gene are well-characterized oncogenic drivers that confer susceptibility to targeted MET inhibitors. Recurrent somatic splice site alterations at MET exon 14 (METex14) that result in exon skipping and MET activation have been characterized, but their full diversity and prevalence across tumor types are unknown. Here, we report analysis of tumor genomic profiles from 38,028 patients to identify 221 cases with METex14 mutations (0.6%), including 126 distinct sequence variants. METex14 mutations are detected most frequently in lung adenocarcinoma (3%), but also frequently in other lung neoplasms (2.3%), brain glioma (0.4%), and tumors of unknown primary origin (0.4%). Further in vitro studies demonstrate sensitivity to MET inhibitors in cells harboring METex14 alterations. We also report three new patient cases with METex14 alterations in lung or histiocytic sarcoma tumors that showed durable response to two different MET-targeted therapies. The diversity of METex14 mutations indicates that diagnostic testing via comprehensive genomic profiling is necessary for detection in a clinical setting. SIGNIFICANCE: Here we report the identification of diverse exon 14 splice site alterations in MET that result in constitutive activity of this receptor and oncogenic transformation in vitro. Patients whose tumors harbored these alterations derived meaningful clinical benefit from MET inhibitors. Collectively, these data support the role of METex14 alterations as drivers of tumorigenesis, and identify a unique subset of patients likely to derive benefit from MET inhibitors.

Phase II trial of erlotinib and docetaxel in advanced and refractory hepatocellular and biliary cancers: Hoosier Oncology Group GI06-101.

BACKGROUND: Patients with advanced hepatocellular (HCC) and biliary tract carcinomas (BTC) have poor prognosis. While the EGFR pathway is overactive in HCC and BTC, single agent anti-EGFR therapies confer modest activity. Preclinical data showed synergistic antiproliferative and proapoptotic effects between anti-EGFR therapies and taxanes. We conducted a phase I study of erlotinib and docetaxel in solid tumors, and noted good tolerability and sustained complete (5 years +) and partial responses in patients with HCC and BTC. This trial evaluated the efficacy of erlotinib with docetaxel in refractory hepatobiliary cancers. METHODS: Eligible patients were allowed to have two prior systemic therapies. Docetaxel 30 mg/m2 i.v. was administered on days 1, 8, 15, and erlotinib 150 mg was dosed orally on days 2-7, 9-14, 16-28 of each 28-day cycle. The primary endpoint was 16 weeks progression-free survival (PFS), and secondary endpoints included response, stable disease, and overall survival. Tumor samples were analyzed for KRAS gene mutations and E-cadherin expression by immunohistochemistry (IHC). Patients with BTC and HCC were accrued and assessed in separate strata for the efficacy endpoints, but for the two-stage initial design of the study, combined PFS was considered. A Simon optimal two-stage design tested the hypothesis that the 16-week PFS is ≤ 15% (clinically inactive) versus the alternative of ≥ 30% (warranting further study). RESULTS: Twenty-five patients, 14 with HCC and 11 with BTC, were enrolled. Common toxicities were rash (76%), diarrhea (56%), and fatigue (52%), mostly grade 1 or 2. No objective responses were seen. Seven BTC (64%) and 6 HCC patients (46%) had stable disease as best response, with a median duration of 16.1 weeks (95% CI 3.7-56.3) for BTC, and 17.6 weeks (95% CI 8.1-49.8) for HCC. The 16-week PFS was 64% for BTC (95% CI 29.7-84.5), and 38% for HCC (95% CI 14.1-62.8). Median overall survival was 5.7 and 6.7 months for BTC and HCC patients, respectively. BTC patients with grade ≥ 2 rash had higher median PFS (6.2 vs 2.2 months) and OS (14.2 vs. 4.2 months). HCC patients with negative/low E-cadherin expression had higher median PFS (6.7 vs. 2.1 months) and OS (14.5 vs. 4 months). CONCLUSION: Erlotinib with docetaxel met the 16-week PFS ≥ 30% endpoint, but overall survival was comparable to that seen with single-agent erlotinib. With the limitation of small numbers of patients, grade ≥ 2 rash (in BTC), and negative/low E-cadherin expression (HCC) were associated with higher PFS and OS. Discussion Refractory biliary tract and hepatocellular cancers are difficult to treat, and no chemotherapy or biologically targeted therapies have impacted survival. Based on preclinical synergism and prior phase I data, we conducted a multi-institutional study sequentially combining the EGFR-targeted agent erlotinib with docetaxel. Results from this study show that the primary endpoint, 16-week PFS of ≥ 30%, was met for the combined group of BTC and HCC patients (as originally planned in the study design), as well as in each disease category: 63.6% for BTC and 38.5% for HCC patients. Nevertheless, no patients attained an objective response and the median survival of 5.7 months for BTC, and 6.7 months for HCC patients (while heavily pretreated), is comparable to that seen with single-agent EGFR-targeted therapies. Safety analysis shows that this regimen was generally well tolerated, and most adverse events were grade 1 or 2. Few patients had reversible grade 3 transaminase elevation (8%), and severe anorexia, fatigue, and rash were uncommon. As expected, patients with grade ≥ 2 rash experienced higher PFS and OS, but this was noted only among the BTC group, likely because too few HCC patients had grade ≥ 2 rash. KRAS is an important predictive marker for anti-EGFR therapies for lung and colorectal cancers, but for HCC or the heterogeneous group of BTC (with 10-50% KRAS mutations) no significant correlations have been established. We were not able to identify a correlation between KRAS and benefit from erlotinib-based therapy, as all but one HCC patient had KRAS wild type gene status. Preclinical data in multiple tumor types showed that E-cadherin, a signature marker for an "epithelial" tumor phenotype when overexpressed, predicts EGFR pathway activation and determines sensitivity to EGFR-targeted agents. E-cadherin is often seen as a poor prognostic marker when downregulated, as noted during cancer progression. Not all studies demonstrate beneficial effects from E-cadherin overexpression, possibly due to histological expression variability or tumor type specificity for this biomarker. Six BTC and 8 HCC patients had evaluable tumor samples for E-cadherin analysis. While the numbers were small and conclusions should be viewed with caution, negative/low E-cadherin expression was associated with improved PFS and OS for hepatobiliary cancers (most significant in HCC) in this refractory patient population where we expected lower expression levels. In conclusion, the combination of erlotinib with docetaxel provided a 16-week PFS of ≥ 30% but showed no appreciable differences in overall survival from historical data with single-agent erlotinib. While EGFR represents an important target in this group of malignancies, it is clear that hepatobiliary cancers are heterogeneous, thus a meaningful improvement in survival most likely will require careful treatment selection based on patient tumor's molecular and genetic profiling.