Although appendectomy is still the most effective treatment for acute appendicitis, nonoperative management is increasingly common, as recent studies—such as one published in November 2020 in The New England Journal of Medicine and a second published in December 2021 in the same journal—have shown that antibiotics can be an effective initial treatment for many patients.

A new analysis of cases in the National Cancer Database (NCDB) has found, however, that there is an increased risk of appendiceal cancer for younger patients (younger than 50 years old). The increase appears to be driven by a rise in carcinoids, a slow-growing type of neuroendocrine tumor, according to study findings published by Salazar et al in the Journal of the American College of Surgeons.

“There is no good answer as to why there is an increase in carcinoids. It could be due to environmental reasons, or it could be due to better diagnostics technology,” said lead study author Michelle Salazar, MD, MHS, a general surgery resident at Yale School of Medicine/Yale New Haven Hospital.

Since surgery provides the only definitive diagnosis of appendiceal cancer, the authors are concerned that acute appendicitis patients who receive nonoperative management could face a delay in their cancer diagnosis.

“I would counsel patients based on age,” Dr. Salazar said. “If you’re older, you are at less risk for appendiceal cancer and [at] greater risk for complications from surgery. Younger, healthy patients are more likely to be able to tolerate an operation and may want to rule out cancer by undergoing the operation. The characteristics of appendicitis should be considered in the decision.”

The study underscores the fact that cancer of the appendix is a “small but real risk” and that patients with acute appendicitis should receive thorough review, said Nader Hanna, MD, FACS, Professor of Surgery and Director of Clinical Operations, Division of General and Oncologic Surgery at the University of Maryland School of Medicine. Dr. Hanna reviewed the study but was not part of the research team.

Study Details

The study was a retrospective analysis of the NCDB, a clinical oncology database sourced from hospital registry data that are collected in more than 1,500 Commission on Cancer (CoC)-accredited facilities. Created and administered by the American Cancer Society and the American College of Surgeons, the NCDB captures 70% of new cancer diagnoses in the United States from facilities accredited by the CoC.

The researchers queried the NCDB for data on patients aged 18 years or older who were diagnosed with a right-sided colon cancer from 2004 to 2017 and underwent appendectomy. All patients with appendiceal cancer were identified, and that group was further divided into patients with carcinoid tumors and those diagnosed with other types of appendiceal cancer. Trends were also evaluated in several age groups, including younger than 40 and each decade beyond starting with age 40.

Key Findings

A total of 387,867 patients were identified with a right-sided colon cancer, which included 19,570 patients with appendiceal cancer. Of those with appendiceal cancer, 5,628 patients (28.7%) had carcinoid tumors.

Patients with appendiceal cancer tended to be younger than age 50 and to have fewer comorbidities but were also more likely to have more advanced disease when compared with patients with other right-sided colon cancers. For example, patients under the age of 40 accounted for 1.4% of other right-sided colon cancers and 8.4% of appendiceal cancers, while patients aged 70 and older accounted for 58.2% of other right-sided colon cancers and 25.3% of appendiceal cancers.

The yearly frequency of appendiceal cancers in the database more than doubled from 814 patients in 2004 to 1,928 cases in 2017, while other right-sided colon cancer cases were even or slightly down—from 26,445 cases in 2004 to 24,712 cases in 2017. As a result, the proportion of appendiceal cancer to other right-sided colon cancers rose over those years, especially in patients aged 40 to 49 years old, for whom the proportion increased from 10% to 18%.

The patient group most likely to have appendiceal cancer compared with other right-sided colon cancers were those who were younger than 40 years old (25% more likely).

Treatment for Appendicitis

The decision whether to treat with antibiotics or surgery should be shared between patient and doctor. For example, there are reasons that patients with appendicitis may want to postpone surgery—they may be traveling, lack health insurance, or have significant comorbidities, Dr. Hanna said.

There are also some precautionary recommendations to consider for older patients with acute appendicitis, said Dr. Hanna. Imaging and pathology reports for patients with acute appendicitis patients aged 50 or older should be closely reviewed, since they are more at risk for more aggressive types of appendiceal cancer, such as adenocarcinoma, he explained.

“Especially in older patients, if close review of the imaging raises suspicions that it would not be a routine appendectomy, the patient should likely be referred to a surgical oncologist.”

Disclosure: For full disclosures of the study authors, visit journals.lww.com/journalacs.