The average age of diagnosis is 38 years: what is this rare and varied cancer that killed Adan Canto ?

Tumeurs de l’appendice : des cancers rares et très variés

He appeared in X-Men: Days of Future Past and played in the series Cleaning Lady and Designated Survivor. Mexican actor Adan Canto died this Monday, January 8, 2024 at the age of 42, after battling a form of appendix cancer.

A "shape" because appendicular cancers represent a very varied family whose treatment is based on expertise in digestive oncology, in dedicated centers.

The ileocaecal appendix, simply called appendix in common parlance, is an element of the digestive tract, a small excrescence in the extension of the large intestine. Its role within the body is not clearly defined and the appendix is ​​best known for its possible inflammation, appendicitis.

A much rarer event, the appendix can also be the site of cancer. We remember in particular the British actress Audrey Hepburn, who, at the beginning of 1993, died in just a few weeks after the announcement of her diagnosis with devastating cancer of the year. appendix.

A broad classification of tumors

Appendicular cancers are cancers of the appendix. These are rare cancers (0.12 cases per 1 million people, according to the National Cancer Institute's Surveillance, Epidemiology and End-Results) and are most often discovered incidentally during a appendectomy (0.9 to 1.4% of appendectomies) or during imaging.

The vast majority of tumors of the appendix are neuroendocrine tumors also called carcinoid tumors. "Neuroendocrine neoplasms constitute a group of tumors, likely to arise anywhere in the body and characterized by their capacity to secrete hormones in approximately 30% of cases. The most common sites of these tumors are the lung and the digestive tract, explains the Gustave Roussy Institute on its website.

15.7% of these endocrine tumors are located in the appendix. For this type of tumor in general, the average age of diagnosis is 38 years with a male predominance. Other appendicular tumors mainly concern epithelial tumors – which affect the cells lining the inside of the appendix.

These are non-mucinous adenocarcinomas (which do not secrete mucus) in 25% of cases, mucinous tumors, also called mucinous adenocarcinomas when they are invasive. Finally, we speak of pseudomyxoma peritonei when the mucinous tumors reach the peritoneum.

Note that the appendix can very rarely be the site of lymphomas, paragangliomas or even metastases.

What symptoms ?

"Neuroendocrine tumors are frequently functional and mainly produce serotonin", underlines the Swiss Medical Review. They can then cause a carcinoid syndrome, the signs of which are: redness, hypotension, tachycardia and significant diarrhea.

Otherwise, 50% of patients are asymptomatic or present with non-specific symptoms. "In other cases, it may be acute abdominal pain (which may mimic acute appendicitis) or chronic, an abdominal mass or weight loss", specifies the French National Society of Gastroenterology.

What support ?

Tumours of the appendix being extremely rare, they therefore require a special approach. In France, the protocol, established by the French National Society of Gastroenterology (SNFGE) is strict.

"Given the rarity of certain situations, the decision on the therapeutic strategy, adapted to each patient, requires a specialized pre-therapeutic assessment, a clinical examination by a surgeon specialized in the management of rare peritoneal tumors and a discussion in a specialized multidisciplinary consultation meeting (RCP), RCP RENAPE (National Network for the Management of Rare Peritoneal Tumors), set up in the reference centers belonging to this network, continues the learned society.

The treatment is primarily surgical. A simple appendectomy is sometimes sufficient when the tumor is small and the risk of lymph node and peritoneal involvement is low. Sometimes, a right colectomy (removal of part of the colon) is necessary for high-risk tumors larger than 2 cm and in mucinous adenocarcinomas.

Cytoreduction is also recommended in cases of damage to the peritoneum (common complication) coupled with HIPEC (hyperthermic intraperitoneal chemotherapy with oxaliplatin). Chemotherapy is placed directly into the cavity of the peritoneum, the inner lining of the abdomen.

For tumors that secrete mucus, the risk during the intervention is the rupture of a mucocele, a pocket of mucus, which could enter the peritoneum. This is why it is essential that the patient is taken care of in a specialized center.

What are the prognoses for these tumors ?

The majority of these tumors are “slow in progression and have a rather good prognosis”, assures the Swiss Medical Review. The prognosis is excellent for certain neuroendocrine tumors (type 1 and often small) but they can sometimes be very aggressive or associated with a high risk of metastases.

"Five-year survival is 93% for neuroendocrine tumors, 55% for intestinal-type adenocarcinomas, 58% for mucinous adenocarcinomas and 27% for those with a cellular component in a kitten ring (large vacuole of mucus which pushes the flattened nucleus to one pole of the cell, editor's note)", completes the Swiss review.