A New Chromatin-Cytoskeleton Link in Cancer

Pancreatic INI1-deficient undifferentiated rhabdoid carcinoma achieves complete clinical response on gemcitabine and nab-paclitaxel following immediate progression on FOLFIRINOX: a case report

INTRODUCTION

INI1-deficient undifferentiated rhabdoid carcinoma is a rare pancreatic carcinoma for which the optimal treatment is unknown. Pancreatic ductal adenocarcinoma, the most common histology of pancreas cancer, is treated with combination chemotherapy in the advanced setting, a strategy supported by strong evidence in well powered studies. In patients with excellent performance status, first-line treatment usually consists of the three-drug regimen FOLFIRINOX, with the combination of gemcitabine with nab-paclitaxel, typically less toxic than the three-drug regimen, reserved for second-line therapy. Given the lack of published reports describing treatment outcomes for patients with rare forms of pancreatic cancer, the same treatment approach used for pancreatic ductal adenocarcinoma is typically employed.

OBSERVATION

This case describes a patient with metastatic pancreatic INI1-deficient undifferentiated rhabdoid carcinoma who was primarily resistant to FOLFIRINOX therapy but who then achieved an immediate, marked and sustained response to gemcitabine with nab-paclitaxel.

CONCLUSION

Given the lack of data informing on optimal management of INI1-deficient pancreatic undifferentiated rhabdoid carcinoma, and the exceptional response achieved by gemcitabine with nab-paclitaxel, this case report highlights a surprising and potentially informative anecdote. Additional studies are needed to confirm responses observed in this report which when taken together may strongly influence first-line therapy choice for this rare malignancy. Given the difficult in acquiring sufficient numbers of these rare histologies in any one institution, multi-institution collaboration in studying outcomes of rare pancreatic malignancies is likely essential.

Clear cell renal cell carcinoma ontogeny and mechanisms of lethality

The molecular features that define clear cell renal cell carcinoma (ccRCC) initiation and progression are being increasingly defined. The TRACERx Renal studies and others that have described the interaction between tumour genomics and remodelling of the tumour microenvironment provide important new insights into the molecular drivers underlying ccRCC ontogeny and progression. Our understanding of common genomic and chromosomal copy number abnormalities in ccRCC, including chromosome 3p loss, provides a mechanistic framework with which to organize these abnormalities into those that drive tumour initiation events, those that drive tumour progression and those that confer lethality. Truncal mutations in ccRCC, including those in VHL, SET2, PBRM1 and BAP1, may engender genomic instability and promote defects in DNA repair pathways. The molecular features that arise from these defects enable categorization of ccRCC into clinically and therapeutically relevant subtypes. Consideration of the interaction of these subtypes with the tumour microenvironment reveals that specific mutations seem to modulate immune cell populations in ccRCC tumours. These findings present opportunities for disease prevention, early detection, prognostication and treatment.