Cancer risk in achalasia
Achalasia is a rare esophageal motility disorder that may predispose patients to increased risk of both squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the esophagus. Reported incidence of malignancy remains controversial in the literature, ranging from a 5- to 50-fold increased risk in comparison to the normal population. This raises the question of mandating surveillance for early diagnosis of malignancy, allowing curative therapy. The current literature was reviewed, focusing on the prevalence and incidence of cancer development in Achalasia patients. Following the PRISMA group guidelines, we evaluated the published studies and overviews on the topic over the last 60 years. We searched for a combination of “achalasia and cancer”. Search criteria were limited to studies with well-documented follow-up and tracking of malignant progression. Twenty-six studies were selected (>30 patients), with median follow up time of 9.2 years (range, 2–23.2 years). Prevalence of cancer in 8,720 patients had a median of 2.45% (range, 0–18.7%), with median incidence of 270 cancer cases per 100,000 patients at risk per year (range, 0–4,545). The time interval between “onset of symptoms” and cancer diagnosis carried a median of 21.8 years (range, 17–28 years). The time interval between the diagnosis of achalasia and the diagnosis of cancer had a median of 10.9 years (range, 5.7–17.2 years). In conclusion, our review of the current literature shows that most studies suggest that patients with achalasia have increased cancer risk, whether as a result of retention esophagitis, or chronic reflux after procedural intervention. Surveillance is therefore justified in select high-risk patients.