Rare cancers: the greatest inequality in cancer research and oncology treatment

Strong association between reduction of late-stage cancers and reduction of cancer-specific mortality in meta-regression of randomized screening trials across multiple cancer types

BACKGROUND

Late-stage cancer incidence has been proposed as an early surrogate for mortality in randomized controlled trials (RCTs) of cancer screening; however, its validity has not been systematically evaluated across screening RCTs of different cancers.

METHODS

We conducted a meta-regression analysis of cancer screening RCTs that reported both late-stage cancer incidence and cancer mortality. Based on a systematic literature review, we included 33 RCTs of screening programs targeting seven cancer types, including lung (n = 12), colorectal (n = 8), breast (n = 5), and prostate (n = 4), among others. We regressed the relative reduction of cancer mortality on the relative reduction of late-stage cancer incidence, inversely weighted for each RCT by the variance of estimated mortality reduction.

RESULTS

Across cancer types, the relative reduction of late-stage cancer incidence was linearly associated with the relative reduction of cancer mortality. Specifically, we observed this association for lung (R2 = 0.79 and 0.996 in three recent large trials), breast (R2 = 0.94), prostate (R2 = 0.98), and colorectal cancer (R2 = 0.75 for stage III/IV cancers and 0.93 for stage IV cancers). Trials with a 20% or greater reduction in late-stage cancers were more likely to achieve a significant reduction in cancer mortality. Our results also showed that no reduction of late-stage cancer incidence was associated with no or minimal reduction in cancer mortality.

CONCLUSIONS

Meta-regression of historical screening RCTs showed a strong linear association between reductions in late-stage cancer incidence and cancer mortality.

Unraveling molecular signatures in rare bone tumors and navigating the cancer pathway landscapes for targeted therapeutics

Rare cancers (RCs), which account for over 20% of cancer cases, face significant research and treatment challenges due to their limited prevalence. This results in suboptimal outcomes compared to more common malignancies. Rare bone tumors (RBTs) constitute 5-10% of rare cancer cases and pose unique diagnostic complexities. The therapeutic potential of anti-cancer drugs for RBTs remains largely unexplored. Identifying molecular alterations in cancer-related genes and their associated pathways is essential for precision medicine in RBTs. Small molecule inhibitors and monoclonal antibodies targeting specific RBT-associated proteins show promise. Ongoing clinical trials aim to define RBT biomarkers, subtypes, and optimal treatment contexts, including combination therapies and immunotherapeutic agents. This review addresses the challenges in diagnosing, treating, and studying RBTs, shedding light on the current state of RBT biomarkers, potential therapeutic targets, and promising inhibitors. Rare cancers demand attention and innovative solutions to improve clinical outcomes.

The efficacy of immunotherapy and chemoimmunotherapy in patients with advanced rare tumors: A Turkish oncology group (TOG) study

INTRODUCTION

The advances in immune checkpoint inhibitors (ICIs) were relatively slow in rare tumors. Therefore, we conducted a multi-center study evaluating the efficacy of ICI monotherapy and the combination of ICIs with chemotherapy (CT) in patients with advanced rare tumors.

METHODS

In this retrospective cohort study, we included 93 patients treated with ICIs for NCI-defined rare tumors from the 12 cancer centers in Turkey. The primary endpoints were the overall response (ORR) and disease control rate (DCR).

RESULTS

The cohort's median age was 56, and 53.8% of the patients were male. The most frequent diagnosis was sarcoma (29%), and 81.7% of the patients were previously treated with at least one line of systemic therapy in the advanced stage. The ORR and DCR were 36.8% and 63.2%, respectively. The germ cell tumors had the lowest ORR (0%), while the Merkel cell carcinoma had the highest ORR to ICIs (57.1%). Patients treated with ICI + ICI or ICI plus chemotherapy combinations had higher ORR (55.2% vs. 27.6%, p = 0.012) and DCR (82.8% vs. 53.4%, p = 0.008). The median OS was 13.47 (95% CI: 7.79-19.15) months, and the six and 12-month survival rates were 71% and 52%. The median duration of response was 16.59 months, and the 12-month progression-free survival rate was 66% in responders. The median time-to-treatment failure was 5.06 months (95% CI: 3.42-6.71). Three patients had high-grade irAEs with ICIs (grade 3 colitis, grade 3 gastritis, and grade 3 encephalitis in one patient each).

CONCLUSION

We observed over 30% ORR and a 13-month median OS in patients with rare cancers treated with ICI monotherapy or ICI plus CT combinations. The response rates to ICIs or ICIs plus CT significantly varied across different tumor types. Responding patients had over 2 years of survival, highlighting a need for further trials with ICIs for patients with rare tumors.

The diagnosis and treatment for a patient with cancer of unknown primary: A case report

Background: Cancer of unknown primary (CUP) is a class of metastatic malignant tumors whose primary location cannot be determined. The diagnosis and treatment of CUP are a considerable challenge for clinicians. Herein, we report a CUP case whose corresponding primary tumor sites were successfully identified, and the patient received proper treatment. Case report: In February 2022, a 74-year-old woman was admitted to the Medical Oncology Department at Sir Run Run Shaw Hospital for new lung and intestinal tumors after more than 9 years of breast cancer surgery. After laparoscopically assisted right hemicolectomy, pathology revealed mucinous adenocarcinoma; the pathological stage was pT2N0M0. Results from needle biopsies of lung masses suggested poorly differentiated cancer, ER (-), PR (-), and HER2 (-), which combined with the clinical history, did not rule out metastatic breast cancer. A surgical pathology sample was needed to determine the origin of the tumor tissue, but the patient's chest structure showed no indications for surgery. Analysis of the tumor's traceable gene expression profile prompted breast cancer, and analysis of next-generation amplification sequencing (NGS) did not obtain a potential drug target. We developed a treatment plan based on comprehensive immunohistochemistry, a gene expression profile, and NGS analysis. The treatment plan was formulated using paclitaxel albumin and capecitabine in combination with radiotherapy. The efficacy evaluation was the partial response (PR) after four cycles of chemotherapy and two cycles combined with radiotherapy. Conclusion: This case highlighted the importance of identifying accurate primary tumor location for patients to benefit from treatment, which will provide a reference for the treatment decisions of CUP tumors in the future.

Big data in basic and translational cancer research

Historically, the primary focus of cancer research has been molecular and clinical studies of a few essential pathways and genes. Recent years have seen the rapid accumulation of large-scale cancer omics data catalysed by breakthroughs in high-throughput technologies. This fast data growth has given rise to an evolving concept of 'big data' in cancer, whose analysis demands large computational resources and can potentially bring novel insights into essential questions. Indeed, the combination of big data, bioinformatics and artificial intelligence has led to notable advances in our basic understanding of cancer biology and to translational advancements. Further advances will require a concerted effort among data scientists, clinicians, biologists and policymakers. Here, we review the current state of the art and future challenges for harnessing big data to advance cancer research and treatment.

Patient-derived xenografts and in vitro model show rationale for imatinib mesylate repurposing in HEY1-NCoA2-driven mesenchymal chondrosarcoma

Mesenchymal chondrosarcoma (MCS) is a high-grade malignancy that represents 2-9% of chondrosarcomas and mostly affects children and young adults. HEY1-NCoA2 gene fusion is considered to be a driver of tumorigenesis and it has been identified in 80% of MCS tumors. The shortage of MCS samples and biological models creates a challenge for the development of effective therapeutic strategies to improve the low survival rate of MCS patients. Previous molecular studies using immunohistochemical staining of patient samples suggest that activation of PDGFR signaling could be involved in MCS tumorigenesis. This work presents the development of two independent in vitro and in vivo models of HEY1-NCoA2-driven MCS and their application in a drug repurposing strategy. The in vitro model was characterized by RNA sequencing at the single-cell level and successfully recapitulated relevant MCS features. Imatinib, as well as specific inhibitors of ABL and PDGFR, demonstrated a highly selective cytotoxic effect targeting the HEY1-NCoA2 fusion-driven cellular model. In addition, patient-derived xenograft (PDX) models of MCS harboring the HEY1-NCoA2 fusion were developed from a primary tumor and its distant metastasis. In concordance with in vitro observations, imatinib was able to significantly reduce tumor growth in MCS-PDX models. The conclusions of this study serve as preclinical results to revisit the clinical efficacy of imatinib in the treatment of HEY1-NCoA2-driven MCS.

The potential long-term comparative effectiveness of larotrectinib vs standard of care for treatment of metastatic TRK fusion thyroid cancer, colorectal cancer, and soft tissue sarcoma

BACKGROUND: Larotrectinib is approved for patients with metastatic TRK fusion cancers, including differentiated thyroid (DTC), colorectal cancer (CRC), and soft tissue sarcoma (STS). Given the basket clinical trial design of larotrectinib, direct comparisons against standard of care in each of the mentioned cancers have not been assessed. Also, owing to the limited duration of follow-up in clinical trials, long-term outcomes for treatments are generally not known or estimated. OBJECTIVE: To compare expected life-years (LYs) and quality-adjusted life-years (QALYs) for patients with metastatic DTC, CRC, and STS who are eligible to receive larotrectinib against patients with unknown NTRK gene fusion status receiving standard-of-care therapy. METHODS: We developed a partitioned survival model to estimate the long-term comparative effectiveness of larotrectinib and standard of care for 3 tumor types. Larotrectinib survival data, assessed by independent review committee, were derived from an updated July 2020 analysis of 19, 8, and 23 adult patients (aged ≥ 18 years) with metastatic TRK fusion DTC, CRC, and STS, respectively. The DTC survival data also included 2 patients aged less than 18 years for a total of 21 patients. Survival estimates for standard of care were derived from published clinical trials. Progressionfree and overall survival for all treatments were estimated using survival distributions (Exponential, Weibull, Log-logistic, and Lognormal) fit to the available data. The final exponential form was selected based on goodness-of-fit and clinical plausibility. QALYs were estimated by adjusting the time spent in the preprogression and postprogression health states by utility weights derived from publicly available literature. RESULTS: Patients receiving larotrectinib experienced more LYs and QALYs compared with those receiving standard-of-care treatments across all 3 assessed cancer types. In DTC, patients receiving larotrectinib had 7.15-8.26 additional LYs (5.87-6.12 QALYs); in CRC, patients receiving larotrectinib had 1.26-1.27 additional LYs (1.00 QALYs); and in STS, patients receiving larotrectinib had 5.56 additional LYs (1.99 QALYs). CONCLUSIONS: Compared with standard of care in metastatic TRK wild-type cancers, larotrectinib is estimated to result in improved LY and QALY outcomes based on parametric extrapolations of intrial survival data. Because patient-level data were unavailable for adjusted analyses, a cross-trial comparison was performed. Given the limitations of this analytic approach and the small sample size for larotrectinib in trials, future studies should reassess the comparative effectiveness of larotrectinib vs standard of care as treated patients accrue and long-term survival data mature. DISCLOSURES: K. Suh, J. Carlson, and S. Sullivan report consulting fees from Bayer US LLC. F. Xia and T. Williamson are employees of Bayer US LLC. This study was funded by Bayer US LLC. The sponsor had no role in the design of the study and did not have any role in the execution, analyses, interpretation of the data, or decision to submit results.

Systematic review of the CUP trials characteristics and perspectives for next-generation studies

BACKGROUND

Research on therapeutic strategies for patients with unknown primary cancer (CUP) has been underwhelming. This paper summarized and evaluated the CUP therapeutic research over the previous five years. Based on this evaluation, recommendations for clinical trial designs are made to improve the impact of CUP research on patients.

METHODS

Published and ongoing research were evaluated. PubMed was searched from January 1, 2015, to November 1, 2021. The start date of 2015 was chosen to identify research published after ESMO issued new diagnostic and therapeutic guidelines. The US National Library of Medicine indexed ongoing clinical trials.

FINDINGS

Of the 244 CUP studies indexed in PubMed, 11.9% were prospective studies, and 4.9% were clinical trials. The review protocol deemed 65 publications eligible for full-text review. Eleven studies evaluating therapeutic regimens were retained. The two prospective studies and non-randomized trials showed promising outcomes for site-specific treatments. Randomized clinical trials were less promising; however, the trials had recruitment challenges resulting in biased accrual and the inability to keep pace with advancing diagnostics and therapeutics. Most of the 35 ongoing studies were phase II single-arm trials assessing immune checkpoint inhibitors (ICI) or site-specific therapies among CUP patients with suspected favorable prognoses.

CONCLUSION

Our evaluation suggests two prospective clinical trial designs that addressed recent study design and recruitment challenges. A visionary approach uses a multi-arm, multistage randomized trial to address rapid advancements in diagnosis and therapy. A pragmatic approach utilizes a single-arm trial with historical controls to overcome comparison group and recruitment challenges.

Cancer taxonomy: pathology beyond pathology

The way we categorise and classify cancer types dictates not only the way we diagnose and treat patients but also many of our decisions on biomarker and drug development. In addition, cancer taxonomy proves the ground truth for future discoveries in the area of computational pathology and artificial intelligence. This editorial comment illustrates the relevance of cancer taxonomy in clinical and morphomolecular diagnosis, prognosis and therapeutic prediction; it shows its importance in identifying the epidemiology, aetiology and pathogenesis in oncology and explains its determinant role in computational tissue-based cancer diagnosis.