JCO precision oncology最新文献

Purpose: Less than 5% of GI stromal tumors (GISTs) are driven by the loss of the succinate dehydrogenase (SDH) complex, resulting in a pervasive DNA hypermethylation pattern that leads to unique clinical features. Advanced SDH-deficient GISTs are usually treated with the same therapies targeting KIT and PDGFRA receptors as those used in metastatic GIST. However, these treatments display less activity in the absence of alternative therapeutic options. Therefore, it is critical to identify novel actionable alterations in SDH-deficient GIST.

Patients and methods: We performed a single-center, retrospective analysis of patients with SDH-deficient GIST together with next-generation sequencing (NGS) analysis from their respective tumor samples to identify mutations and copy number alterations and chromosomal alterations. NGS-tailored treatment was implemented whenever possible.

Results: Seventeen tumor samples from 14 patients with SDH-deficient GIST underwent NGS. Mutational load was low, although three patients (21%) displayed molecular events in relapse samples leading to PI3K/mTOR pathway hyperactivation. mTOR inhibition with everolimus obtained a sustained tumor response in a heavily pretreated patient. Other alterations, largely present in late-stage patients, uncovered genes involved in cell cycle regulation, telomere maintenance, and DNA damage repair. Chromosomal arm-level alterations differed from the canonical cytogenetic progression in KIT/PDGFRA-mutant GIST.

Conclusion: This molecular landscape of SDH-deficient GIST uncovers novel molecular alterations, mostly in relapse and/or previously pretreated patients. The identification of genetic events leading to PI3K/mTOR dysregulation together with the remarkable activity of everolimus in one patient showcases the clinical relevance of this pathway, validates the utility of NGS in this population, and poses everolimus as a novel therapeutic alternative. Several other alterations were found at the genetic and genomic levels, underscoring novel biological processes likely involved during tumor evolution.

Purpose: Pancreatic acinar cell carcinoma (PACC) is a rare and aggressive form of pancreatic cancer that originates in the acinar cells of the exocrine pancreas. In this study, we aimed to investigate the clinical and molecular characteristics of patients with PACC at our institution.

Methods: This was a retrospective study of patients with PACC seen at Mayo Clinic between 2002 and 2023. Baseline patient characteristics, tumor pathology, treatment strategies used, and survival outcomes were analyzed. Kaplan-Meier curves were estimated using newsurv macros in SAS.

Results: The study included a total of 65 patients with PACC. The median age at diagnosis was 66 years. Almost half of the patients (48%) presented with resectable/borderline-resectable disease (n = 28). Five-year overall survival (OS) for resectable/borderline-resectable, locally advanced/unresectable, and metastatic disease were 72.0%, 21.6%, and 20.9%, respectively. Somatic and germline next-generation sequencing identified numerous potentially actionable targets including homologous recombination (43% somatic, 33% germline), RAF alterations (29% somatic), and mismatch repair (14% somatic).

Conclusion: Our findings underscore the heterogeneity and aggressive nature of PACC. Despite the improved prognosis for patients with resectable/borderline-resectable disease, OS remains poor, particularly for those with locally advanced or metastatic disease. The identification of actionable molecular targets in a significant proportion of patients highlights the potential for personalized therapeutic approaches. Future research should focus on tailored treatment strategies to exploit these molecular vulnerabilities, which may offer new options for improving outcomes in this rare malignancy.

Purpose: Considerable genetic heterogeneity is currently thought to underlie hereditary prostate cancer (HPC). Most families meeting criteria for HPC cannot be attributed to currently known pathogenic variants.

Methods: To discover pathogenic variants predisposing to prostate cancer, we conducted a familial case-control association study using both genome-wide single-allele and identity-by-descent analytic approaches. Sequence of high-risk haplotype carriers was used for variant detection. Candidate pathogenic variants were tested for association with prostate cancer across independent biobanks for replication of observations.

Results: Pathogenic variants within WNT9B were associated with familial prostate cancer and observations replicated within four of four independent biobanks. WNT9B E152K carried 2.5-fold risk and reached genome-wide significance under meta-analysis, collectively encompassing a half million patients. WNT9B Q47R was also associated with prostate cancer with genome-wide significance among Finns, for which identity-by-descent analyses confirmed a founder effect. WNT9B shares an unexpected commonality with the previously established prostate cancer risk genes HOXB13 and HNF1B: they are each required for embryonic prostate development. With this recognition, we further evaluated two additional genes known to cause Mendelian genitourinary developmental defects, KMT2D and DHCR7. These too were nominally associated with prostate cancer under meta-analyses.

Conclusion: WNT9B and additional genes that are required for early genitourinary development are also involved in the later development of prostate cancer.

Purpose: To investigate whether hormone receptor-positive, human epidermal growth factor receptor 2-low (HR+HER2-low) versus HR+HER2-zero early breast cancers have distinct genomic and clinical characteristics.

Methods: This study included HR+, HER2-negative early breast cancers from patients enrolled in the phase III, randomized BIG 1-98 and SOFT clinical trials that had undergone tumor genomic sequencing. Tumors were classified HR+HER2-low if they had a centrally reviewed HER2 immunohistochemistry (IHC) score of 1+ or 2+ with negative in situ hybridization and HR+HER2-zero if they had an HER2 IHC score of 0.

Results: A total of 1,795 tumors were evaluable for this study (BIG 1-98 n = 520, SOFT n = 1,275). The frequency of HER2-low tumors was 37% and 21% in the postmenopausal BIG 1-98 and premenopausal SOFT cohorts, respectively. There were no significant differences in clinicopathologic variables between HER2-low and HER2-zero groups which was consistent across both trials. There was no significant difference in risk of distant recurrence for patients with HER2-low tumors versus HER2-zero tumors (5-year % distant recurrence-free 94.0% v 92.8%, P = .61, in BIG 1-98; 89.4% v 92.7%, P = .31, in SOFT, respectively). Somatic genomic profiles were similar with the exception of MAP3K1 mutations which were more frequent in HER2-zero tumors (BIG 1-98 19% v 5%, SOFT 11% v 6%). Both ERBB2 copy number and ERBB2 gene expression abundance were significantly higher in HER2-low tumors compared with HER2-zero tumors; however, the absolute difference was small. Correlation between ERBB2 copy number values and gene expression was modest (r = 0.17).

Conclusion: In two large clinical trials with centrally reviewed HER2 IHC, our findings do not support HER2-low breast cancer as a distinct clinical or biologic entity among HR+HER2- early breast cancers. Absolute differences in median ERBB2 copy number levels or gene expression are small and of unclear biologic relevance.

Purpose: Chronoradiobiology has emerged as a potential field of study with therapeutic implications for cancer treatment. We aimed to investigate the association between radiation chronotherapy and the efficacy and toxicity of patients with nasopharyngeal carcinoma (NPC).

Patients and methods: Patients with nonmetastatic NPC treated with intensity-modulated radiotherapy in Fujian Cancer Hospital between January 2017 and December 2019 were included. Propensity score matching (PSM) with 1:1:1 was used to account for selection bias. Cox regression analysis was performed to explore the impact of radiotherapy timing on patient survival. Sensitivity analysis was implemented to determine the size and directional stability.

Results: One thousand forty patients met study inclusion criteria and 332 patients were included in a PSM cohort. In the unmatched cohort analysis, morning radiotherapy exhibited a significantly superior overall survival (OS) outcome (hazard ratio [HR], 0.60 [95% CI, 0.40 to 0.91], adjusted log-rank P = .028) than the afternoon one. After PSM analysis, it was observed that individuals undergoing radiotherapy in the afternoon group (HR, 5.88 [95% CI, 2.55 to 13.58], adjusted log-rank P = .004) and the night group (HR, 4.81 [95% CI, 1.91 to 12.11], adjusted log-rank P = .018) displayed a tendency toward shorter OS compared with the morning group. No significant differences in acute treatment-related adverse effects were observed among the three groups. Morning radiotherapy demonstrated consistent robustness in the multivariable analysis, thereby establishing an association with higher OS. The directionality of the effect size was consistent across sensitivity analysis.

Conclusion: These results underscore the potential benefits of scheduling radiotherapy in the morning for NPC management, although prospective studies are needed to confirm these findings.

Purpose: MAP2K1/MEK1 mutations are potentially actionable drivers in cancer. MAP2K1 mutations have been functionally classified into three groups according to their dependency on upstream RAS/RAF signaling. However, the clinical efficacy of mitogen-activated protein kinase (MAPK) pathway inhibitors (MAPKi) for MAP2K1-mutant tumors is not well defined. We sought to characterize the genomic and clinical landscape of MAP2K1 mutant tumors to evaluate the relationship between MAP2K1 mutation class and clinical activity of MAPKi.

Methods: We interrogated American Association for Cancer Research (AACR) GENIE (v13) to analyze solid tumors with MAP2K1 mutations. We performed a systematic review and meta-analysis of published reports of patients with MAP2K1-mutant cancers treated with MAPKi according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary end point was progression-free survival (PFS), and secondary end points were overall treatment response rate (ORR), duration of response (DOR), and overall survival.

Results: In the AACR GENIE data set, class 2 MAP2K1 mutations (63%) were more prevalent than class 1 (24%) and class 3 (13%) mutations (P < .0001). Co-occurring MAPK pathway-activating mutations were more likely to occur in class 1 versus class 2 or 3 MAP2K1-mutant tumors (P < .0001). Our systematic meta-analysis of the literature identified 46 patients with MAP2K1-mutant tumors who received MAPKi. In these patients, ORR was 28% and median PFS was 3.9 months. ORR did not differ according to MAP2K1 mutation class or cancer type. However, patients with class 2 mutations experienced longer PFS (5.0 months) and DOR (23.8 months) compared with patients with class 1, 3, or unclassified MAP2K1 mutations (PFS 3.5 months, P = .04; DOR 4.2 months, P = .02).

Conclusion: Patients with class 2 MAP2K1 mutations represent a novel subgroup that may derive benefit from MAPKi. Prospective clinical studies with novel MAPKi regimens are warranted in these patients.