Peritoneal Cancer – All that you need to know

Peritoneal cancer is an uncommon type of cancer that involves the peritoneum. This membrane delineates the inner side of the abdominal wall (the parietal layer) as well as most abdominal organs, including the liver, small and large intestines, and stomach (visceral layer). The space between the peritoneum’s two layers is called the peritoneal cavity. The peritoneum covers and protects the abdominal organs by producing peritoneal fluid. The fluid insulates the organs and reduces friction.

Types of Peritoneal Cancers

Peritoneal cancers are broadly classified into primary and secondary types.

Primary Peritoneal Cancer

Primary peritoneal cancer is the one that originates in the peritoneum and is almost always found in women. The occurrence in males is quite rare, but a few incidences have been reported.¹Jermann M, Vogt P, Pestalozzi BC. Peritoneal carcinoma in a male patient. Oncology. 2003;64(4):468-72. doi: 10.1159/000070308. PMID: 12759547. This cancer type is very much analogous to the most common ovarian cancer category, epithelial ovarian cancer. However, peritoneal cancer can develop even in the absence of ovaries.

Secondary Peritoneal Cancer

Secondary peritoneal cancer initially establishes in another abdominal organ (i.e., stomach, ovaries, small/large intestines, etc.) and later spread (via metastasis) to the peritoneal membrane. This type of cancer is much more prevalent than the primary type and affects men and women equally (in contrast to the primary type, i.e., it involves women exclusively).
Furthermore, the cancer cells in secondary peritoneal cancer resemble the cells in the primary organ in which cancer originates. These organs include the stomach, intestines, appendix, and ovaries.

Who is at Risk?

The risk factors that play an important role in the development of peritoneal cancer are listed below, although it is a rare condition.

Factors

• Age (old age carries greater risk)
• Family history of ovarian or peritoneal cancer (especially first-degree relatives)
• Genetic mutations²Iavazzo C, Gkegkes ID, Vrachnis N. Primary peritoneal cancer in BRCA carriers after prophylactic bilateral salpingo-oophorectomy. J Turk Ger Gynecol Assoc. 2016 Jan 12;17(2):73-6. doi: 10.5152/jtgga.2016.15223. PMID: 27403072; PMCID: PMC4922728. known as BRCA1 and BRCA2 (mainly cause ovarian and breast cancers)
• Hormone replacement therapy (HRT), if commenced after menopause
• Obesity
• Endometriosis (a gynecological disease in which the cells resembling uterine tissues implant outside of the uterus)

Symptoms of Peritoneal Cancer

Peritoneal cancers are notorious because they are hard to detect in their initial stages. Their signs and symptoms are ambiguous as they bear a lot of resemblance to those of other diseases. Additionally, once the signs and symptoms of peritoneal cancer become evident, the cancer is already in an advanced stage and metastasizes to other organs.
When peritoneal cancer symptoms do manifest, they include the following:

• Abdominal pain and discomfort, for instance, cramps, gas, bloating, swelling, indigestion, or pressure
• Increased urinary frequency
• Digestive issues, including constipation, diarrhea, or nausea
• A feeling of early fullness when eating or loss of appetite
• Weight loss or gain

As the disease progresses, excessive fluid, medically called ascites, can accumulate in the abdomen leading to a myriad of additional symptoms, including:

• Nausea or vomiting
• Stomach discomfort or pain
• Lack of energy
• Breathlessness
• Abdominal distension
• Lower back pain

Eventually, in the final stages of peritoneal cancer, when it involves abdominal organs and causes their blockage, other symptoms develop, namely:

• Bowel or/and urinary obstruction
• Inability to drink or eat
• Vomiting

How is Peritoneal Cancer Diagnosed?

After taking a thorough history and examination, your doctor might order a few tests to diagnose it, which may include the following:

• Blood tests (to detect CA-125 and HE4, which provide supportive evidence for the presence of cancer)
• Imaging Studies (including ultrasound, CT scan, and MRI; to look for the precise location of the tumor)
• Biopsy – in which a sample of the cancerous tissue is taken and later visualized under the microscope to know the characteristics of the cancer cell types (primary vs. secondary), which aids in treatment planning.
• Laparoscopy – a technique in which a camera is introduced into the abdominal cavity, and internal organs are directly visualized; biopsy may also be taken.
• Paracentesis- if you have excessive fluid in the abdomen (ascites), doctors may use this procedure to take its sample and run some tests

What Treatment Options Are Available for Peritoneal Cancers?

The treatment of peritoneal cancer majorly depends on the severity of the disease. The severity and spread of cancer determine its stage and grade, which in turn will indicate the preferred treatment option.
Although the disease is difficult to treat, the following options are available:

• Surgery involves surgically removing the significant bulk of cancerous cells that might have spread to the abdominal organs. It is also termed cytoreductive procedure.
• Chemotherapy – anticancer drugs are introduced in the body; they may also be heated and directly introduced into the abdomen, also called HIPEC or hyperthermic intraperitoneal chemotherapy)
• Targeted Therapy (which affects the cancer cells only and spares normal body cells)
• Radiotherapy (to treat the residual disease via using radiation)
• Hormonal Therapy

Prognosis of Peritoneal Cancers

Doctors believe that peritoneal cancer, whether primary or secondary, can be deadly. Although the outlook for people has significantly improved over the past years, it still carries a poor prognosis since it is already in an advanced stage by the time of its detection.
As discussed earlier, its symptoms are undoubtedly challenging to recognize. Still, if you are experiencing some general symptoms for a long duration, you need to get a doctor’s appointment to rule out its suspicion. An earlier diagnosis and prompt treatment ensure a better outcome.

Survival Rates

As of the recent data of September 2022, primary peritoneal cancer has a survival rate ranging from 11-17 months. ³Yun WS, Bae JM. Primary peritoneal serous carcinoma, an extremely rare malignancy: A case report and review of the literature. Oncol Lett. 2016 Jun;11(6):4063-4065.The median survival in secondary peritoneal cancer is six months, depending upon the stage of cancer (5-10 months for stages 0, I, and II, and 2-3.9 months for stages III-IV).
The location of the primary tumor also plays its part in determining the survival rates. The cancer of pancreatic origin carries the worst survival rates of all (2.9 months), followed by gastric (6.5 months) and colorectal origin (6.9 months). The simultaneous occurrence of ascites (excessive abdominal fluid) and liver metastasis (spread) negatively impact survival.

Dietary Interventions

Optimizing the diet of cancer patients is essential because they require an increased amount of certain nutrients. To replenish the excessive muscle mass breakdown, it is recommended for these patients to consume low-calorie diets rich in proteins, such as plant-based proteins like beans, legumes, nuts, and seeds, as well as eggs, poultry, and meat. In addition, incorporating diets rich in dietary fiber is recommended to promote regular bowel movements. Ensure that you have small but frequent meals and stay hydrated.

Conclusion

Peritoneal cancers are cancers of the peritoneal cavity that are rare but deadly. They have nonspecific symptoms at presentation, contributing to their late diagnosis and subsequent difficulty in treatment. Although the stage of cancer at presentation mainly governs the treatment strategy, available treatment options do not guarantee a 100% success rate. Nonetheless, researchers are making further advancements to improve future outcomes.

Refrences

• 1
  Jermann M, Vogt P, Pestalozzi BC. Peritoneal carcinoma in a male patient. Oncology. 2003;64(4):468-72. doi: 10.1159/000070308. PMID: 12759547.
• 2
  Iavazzo C, Gkegkes ID, Vrachnis N. Primary peritoneal cancer in BRCA carriers after prophylactic bilateral salpingo-oophorectomy. J Turk Ger Gynecol Assoc. 2016 Jan 12;17(2):73-6. doi: 10.5152/jtgga.2016.15223. PMID: 27403072; PMCID: PMC4922728.
• 3
  Yun WS, Bae JM. Primary peritoneal serous carcinoma, an extremely rare malignancy: A case report and review of the literature. Oncol Lett. 2016 Jun;11(6):4063-4065.