Current Status and Future Directions in Appendiceal Cancer with Peritoneal Dissemination

The Role of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Appendiceal Tumors and Colorectal Adenocarcinomas

Peritoneal surface disease (PSD) has historically been used interchangeably with the term peritoneal carcinomatosis (PC) and has a dismal natural history. A variety of malignant pathologies, including colorectal and appendiceal primary tumors, can disseminate throughout the peritoneal cavity, leading to bowel obstruction and death. In general, peritoneal spread from high-grade appendiceal and colorectal primaries has the potential of hepatic and distant spread and best classified as PC. Low-grade appendiceal tumors are better categorized as PSD, due to low cellularity, high mucin production, and lack of potential spread outside the peritoneal cavity. Growing international experience with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) over the past 30 years has presented a therapeutic option to patients with PSD from colorectal and appendiceal tumors that can provide significant disease control, as well as potential for previously unattainable long-term survival. The proliferation of HIPEC centers and ongoing prospective trials are helping to standardize HIPEC techniques and patient selection.

Preclinical Evaluation of Cathepsin-Based Fluorescent Imaging System for Cytoreductive Surgery

BACKGROUND

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is a treatment option for peritoneal surface malignancies. The ability to detect microscopic foci of peritoneal metastasis intraoperatively may ensure the completeness of cytoreduction. In this study, we evaluated the suitability of a hand-held cathepsin-based fluorescent imaging system for intraoperative detection of appendiceal and colorectal peritoneal metastasis.

METHODS

Peritoneal tumors and normal peritoneal tissues were collected from patients with appendiceal and colorectal peritoneal metastasis. Expression of different cathepsins (CTS-B, -D, -F, -G, -K, -L, -O, and -S) was determined by quantitative RT-PCR and immunohistochemistry. The hand-held cathepsin-based fluorescent imaging system was used to detect peritoneal xenografts derived from human colon cancer cells (HT29, LoVo and HCT116) in nu/nu mice.

RESULTS

While the expression levels of CTS-B, -D, -L, and -S could be higher in peritoneal tumors than normal peritoneum with a median (range) of 6.1 (2.9-25.8), 2.0 (1.0-15.8), 1.4 (0.8-7.0), and 2.1 (1.6-13.9) folds by quantitative RT-PCR, respectively, CTS-B was consistently the major contributor of the overall cathepsin expression in appendiceal and colonic peritoneal tumors, including adenocarcinomas and low-grade appendiceal mucinous neoplasms. Using peritoneal xenograft mouse models, small barely visible colonic peritoneal tumors (<2.5 mm in maximum diameter) could be detected by the hand-held cathepsin-based fluorescent imaging system.

CONCLUSIONS

Because cathepsin expression is higher in peritoneal tumors than underlying peritoneum, the hand-held cathepsin-based fluorescent imaging system could be useful for intraoperative detection of microscopic peritoneal metastasis during CRS-HIPEC and clinical trial is warranted.

"The Jelly Belly": Diagnostic Dilemmas and Current Concepts

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare and poorly understood clinicopathological entity characterized by gelatinous ascites with neoplastic or non-neoplastic mucinous implants in the peritoneum. Although its origin was debated, current evidence in literature favours the appendix as the origin of the disease, over the ovaries. The changing terminologies in the classification of this entity pose diagnostic and management challenges.

CASE REPORTS

Herein, we report three cases of PMP in postmenopausal women, their clinical presentation, pathological staging based on the peritoneal tumor deposits and the treatment administered. Two patients recovered uneventfully, while one had recurrence of adenocarcinoma.

CONCLUSION

The rarity of this disease and the diagnostic challenges associated with it are discussed with an emphasis on the current concepts in its origin and management. Appropriate classification and complete removal of the tumor is mandated to prevent disease-related mortality.

Peritoneal dissemination from high-grade appendiceal cancer treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC)

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have shown variability in survival outcomes when used to treat peritoneal surface disease (PSD) from appendiceal and colorectal cancers. The primary goal of this study was to examine outcomes for high-grade appendiceal (HGA) and high-grade colonic primaries after CRS-HIPEC to determine if a significant difference exists between the two groups.

METHODS

A retrospective analysis of patients with peritoneal dissemination from appendiceal and colonic primaries were identified in a prospectively maintained database of 1,223 CRS-HIPEC procedures performed between 1991 and 2015. Patient demographics, performance status resection status, tumor grade, nodal status, morbidity, mortality, and survival were reviewed with biopsy-proven PSD being classified according to primary site. Univariate and multivariate analyses were performed, and outcomes compared.

RESULTS

The study identified 171 CRS-HIPEC procedures for 165 patients: 110 (66.7%) for HGA and 55 (33.3%) for high-grade colonic lesions. Observed median disease-free survival (DFS) and overall survival (OS) for both groups were the same at14.4 and 18 months, respectively. Median survival according to resection status for R0/R1, R2a, and R2b/c were 36, 15.6, and 8.4 months (P<0.0001). Median OS for those who received preoperative chemotherapy versus those who did not were 14.4 and 20.4 months, respectively (P=0.01). For those who received preoperative chemotherapy, no difference was apparent in the DFS interval (P=0.34). Multivariate predictors of OS included resection status (P<0.0001) and lymph node involvement (P=0.0005).

CONCLUSIONS

Preoperative chemotherapy offered no clear DFS or OS benefit, for HGA or high-grade colon cancer patients. Complete cytoreduction offered the greatest survival benefit to both groups with a correlating drop in survival to resection status. Outcomes for high grade appendiceal cancer are remarkably similar to colon cancer.

The role of VEGFR-2 expression in outcomes and survival of patients with peritoneal carcinomatosis from appendiceal cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) is a prognostic factor and target treatment for metastatic colorectal and ovarian cancer. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has improved survival on peritoneal carcinomatosis (PC) from appendiceal cancer. We hypothesize that tumoral high expression of VEGF receptor 2 (VEGFR-2) is a negative prognostic factor for survival in patients with PC from appendiceal cancer.

METHODS

A retrospective study of a prospective database revealed 89 patients with PC from appendiceal cancer who underwent 127 CRS/HIPECs. Surgical specimens from 59 patients were tested to identify high vs. low VEGFR-2 expression. Patient outcomes and survival were analyzed.

RESULTS

There were 26 males and 33 females. Mean age was 51 years. Forty-seven VEGFR-2 high expressers and 15 low expressers were identified. Mean follow-up of high and low expressers was 25.1 and 26.6 months, respectively (p = 0.806). At follow-up, 33 (70%) high expressers were alive and 14 (30%) deceased, while 11 (92%) low expressers were alive and 1 (8%) deceased. Recurrence, use of bevacizumab, CC score, PCI, and LN status showed no differences between high and low expressers. OS for high expressers was 90.5%, 59.8%, and 47.1% at 1-, 3-, and 5-years, respectively, while OS for low expressers remained stable at 91.7% at 1-, 3-, and 5-years (p = 0.133).

CONCLUSION

There is a trend towards better outcomes and survival in patients with PC from appendiceal cancer who have low expression of VEGFR-2 compared to high expression. More studies are encouraged to confirm this trend.