Staging of Peritoneal Cancer

Methods of evaluating the extent of peritoneal carcinomatosis, or spread of cancerous tumors into the abdomen, are sometimes used to help determine treatment and prognosis for peritoneal cancers. Below are some of the scoring methods used to evaluate peritoneal cancer and to help determine treatment regimens and prognosis. This is not a complete list. Others not included here are the Gilly Peritoneal Carcinomatosis Staging method and the Simplified Peritoneal Cancer Index.

Peritoneal Cancer Index (PCI): A scoring system signifying the extent of metastasis into the peritoneal cavity. The abdomen and pelvis are divided into 13 identified regions. For each region, a Lesion Size (LS) score is calculated for the largest tumor in that region (not the number of tumors in the area, just the size of the largest tumor in that particular region).

If there are no tumor nodules in a region, a score of zero is given to that region (LS-0).
If tumor nodules in a region are smaller than 0.5 cm, an LS score of one (LS-1) is given to that region.
If a region has tumor nodules from 0.5-5.0 cm present, it is given a lesion size score of two (LS-2).
If a region has tumor nodules greater than 5.0 cm or if it has tumors that converge (join together), that section is given a score of three (LS-3).

The lesion size scores for each of the thirteen regions are added together. The highest score possible is 39 (13 times 3). Lower PCI scores are generally associated with a better prognosis and a greater likelihood of successful cytoreduction (debulking) surgery . PCI scores can be calculated before cytoreduction (debulking) surgery and after. It is possible for a PCI of 39 prior to cytoreduction surgery to become a PCI of 0 after surgery if all tumors are removed. It is also possible to have a low PCI score but a prognosis that is not as good if tumors are located in areas not accessible to surgical removal.

Completeness of Cytoreduction (CC) Score: Cytoreduction surgery attempts to remove all tumors in the peritoneal cavity (peritoneal surface malignancies/peritoneal carcinomatosis). It is not always possible to remove all tumors. The success of this surgery is scored as follows-

CC-O All tumors are removed during cytoreduction surgery, and there is no visible cancer in the abdomen the at completion of the surgery
CC-1 Tumor nodules remain in the abdomen or pelvis after surgery but are less than 2.5 mm in size
CC-2 Tumor nodules remain in the abdomen or pelvis and are between 2.5 mm and 2.5 cm in size
CC-3 Tumor nodules greater than 2.5 cm or a confluence (merging) of non-removable tumor nodules remain at any site in the abdomen or pelvis after surgery

A complete cytoreduction provides the best chance at long term survival. For minimally invasive and low grade mucinous tumors that are more easily penetrated by intraperitoneal chemotherapy, CC-0 and CC-1 cytoreduction scores are considered "complete" cytoreduction. For intermediate and high grade tumors, only a score of CC-0 is considered a complete cytoreduction. Post-operative cytoreduction surgery scores of CC-2 and CC-3 are not usually associated with long-term survival.

Complete cytoreduction, regardless of histology, is associated with a higher likelihood of long term survival. Intraoperative Hyperthermic Intraperitoneal Chemotherapy is used in combination with cytoreduction surgery to kill microscopic cells released into the peritoneal cavity from tumors during surgery or to kill cells released into the abdomen in cases of appendiceal rupture. Intraoperative Hyperthermic Intraperitoneal Chemotherapy may be used after hemicolectomy in cases of appendix rupture even when no other peritoneal tumors are present as theoretically the rupture has seeded the abdomen with microscopic cancer cells.

Prior Surgical Score: Definitive treatment for peritoneal carcinomatosis using debulking surgery and intraperitoneal chemotherapy is best when it is the initial treatment for this cancer. In some cases, a patient has had surgery without intraperitoneal chemotherapy for peritoneal metastasis prior to cytoreduction (debulking) surgery and intraperitoneal chemotherapy. The prior surgical score (PSS) gives a number value to surgeries done prior to the attempt at debulking/peritoneal chemotherapy treatment. As in the Peritoneal Cancer Index, the abdomen is divided into regions, in this case 9 regions.

If a patient has had no prior surgery or only a only a biopsy, they are given a Prior Surgical Score of 0 (PSS-0).
A Prior Surgical Score of 1 (PSS-1) is given if surgery was done in only one of the abdominal regions.
A Prior Surgical Score of 2 (PSS-2) is given if 2 to 5 regions of the abdomen have previously had surgery.
A Prior Surgical Score of 3 (PSS-3) is given more than 5 regions have had surgical intervention.

Because scar tissue can trap cancer cells from previous surgeries, and because prior surgery may have caused raw sites to be open for deeper invasion of cancer cells that are more difficult to remove at later surgeries, a Prior Surgical Score of 3 (PSS-3) prior to cytoreduction (debulking) surgery and intraperitoneal chemotherapy is associated with reduced survival.

TNM Staging: TNM staging is also used in colorectal cancers. This staging system refers to the status of the tumor (T), lymph nodes (N) and metastasis of the cancer (M). For an explanation of this staging method and others , see American Cancer Society, Inc.-Staging of Colon and Rectal Cancers

Clinical Results of Treatment Peritoneal Surface Malignancy

Prognostic indicators in peritoneal carcinomatosis from gastrointestinal cancer

Lymph Node Metastasis in Epithelial Malignancies of the Appendix With Peritoneal Dissemination Does Not Reduce Survival in Patients Treated by Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy

Prognostic Factors for Colon and Rectal Cancers

This website is for informational and educational purposes only. Readers are encouraged to confirm the information contained herein with other sources. The information on this website is not complete and not intended to replace medical advice offered by physicians or health care providers. Patients and consumers should review the information carefully with their professional health care provider.

Last Updated 05/05/2008 12:17:23 PM