HJBR Sep/Oct 2022

HEALTHCARE JOURNAL OF BATON ROUGE I  SEP / OCT 2022 55 Mohammad Al Efishat, MD Surgical Oncologist and Pancreatic and Hepatobiliary Surgeon Our Lady of the Lake Regional Medical Center and Cancer Institute 13 regions of the abdomen, each region is given a score from zero to three, then a to- tal score is calculated. This score also helps decide which patients are candidate for CRS/ HIPEC; for example, for colorectal perito- neal metastasis, most experts would offer surgery for those with a PCI of 20 or less, while for gastric cancer, the PCI needs to be much lower (less than seven) for a patient to benefit fromCRS/HIPEC. Conversely, for pseudomyxoma peritonei due to mucinous appendiceal neoplasms, the PCI score be- comes less pertinent and aggressive debulk- ing is performed even with large burden of peritoneal disease. For other tumors, like mesothelioma, the histologic subtype plays a more important role, with epithelioid sub- type showing more favorable biological be- havior, while the sarcomatous subtype is more aggressive and surgery is not usually offered for these patients. And lastly, HIPEC for epithelial ovarian cancer is usually re- served for recurrent and advanced cancers following initial cytoreduction surgery. WHO CAN BENEFIT FROM HIPEC SURGERY? Many patients with GI malignancies and peritoneal metastasis can benefit from the surgery. We now differentiate between peritoneal carcinomatosis, which refers to diffuse incurable disease versus limited peritoneal metastasis that can be cured in certain cases. That said, the “ideal” patient for CRS/HIPEC is one with low-grade ap- pendiceal neoplasm (LAMN) with peritoneal mucinous metastasis, or pseudomyxoma peritonei, which is now referred to as dif- fuse peritoneal mucinosis (DPAM). These patients have a high chance for cure and around 80% 10-year survival following CRS/HIPEC. Other appendiceal tumors with higher grade and more aggressive biology (e.g., adenocarcinoma) can also benefit from CRS/HIPEC surgery in which it improves progression-free survival and essentially turns the disease into a chronic, rather than a terminal, disease. Moreover, this surgery can delay or treat multiple sequalae of peri- toneal metastasis including pain, nausea, obstruction, and ascites. Colorectal peritoneal metastasis is per- haps themost common indication for HIPEC in today’s world, given the high incidence of colon cancer, compared to appendiceal neoplasms and peritoneal mesothelioma. The peritoneum is the third most common site of metastasis for colorectal cancer and can be the only site of metastasis in 25% of cases. Two decades ago, these patients had a median survival of five to sevenmonths, and a median survival of 12 months in the era of doublet chemotherapy, while cytoreductive surgery with HIPEC for colorectal peritoneal metastasis have been associated with longer survival of 22 months in studies conducted in the early 2000s. Of note, a recent study (PRODIGE 7) triggered significant debate lesser omentum, the spleen, the ovaries, and debulking of all tumor deposits involving other critical organs. These aforementioned sites are prone for involvement in peritoneal metastasis given that they are involved in the circulation of the normal intrabdominal fluid, which lubricates the intrabdominal or- gans and gets absorbed in the omentum and lacunae near the right diaphragm. Removal of critical structures is only performed after weighing the risks and benefits alongside the biology of the tumor. Once complete, or near complete, cytoreduction is completed, the chemotherapy is given intraperitoneally at much higher doses than the usual IV dose, where traditional methods of chemotherapy cannot effectively reach. Common chemo- therapeutics agents include mitomycin C, cisplatin, doxurubicin, carboplatin, pacli- taxel, and oxaliplatin. The theory is that the higher dosing and the heating of the cyto- toxic chemotherapy increase its penetration into the tissue and augment effectiveness. The intraperitoneal route allows for more effective penetration of peritoneal surfaces than conventional IV chemotherapy. The peritoneal carcinomatosis index is commonly used to evaluate the burden of the peritoneal metastasis and provide a uniform, although somewhat subjective, method of reporting and communicating between medical experts when dealing with this disease. The score is calculated by mea- suring the size of the disease in pre-specified