Rare Cancer Day Date in the current year: September 30, 2025

There are more than 100 types of cancer that can affect humans. The most common types worldwide include breast, lung, colorectal, prostate, stomach, and liver cancer. These cancers account for the largest share of diagnoses globally. In contrast, rare cancers occur in very few people compared to more common cancers. According to most definitions, a cancer is considered rare if it affects fewer than six people per 100,000 each year.

Roughly one in four people diagnosed with cancer has a rare form of the disease. The prognosis varies on a case-by-case basis, but the average five-year survival rate is lower for patients with rare cancers than for patients with more common cancers. This is because rare cancers are less likely to attract significant research funding due to their low prevalence. Less funding means that rare cancers are understudied, slowing the discovery of new diagnostic methods, treatments, and potential cures.

Rare cancers are more frequently misdiagnosed or diagnosed late because many doctors may never encounter a case during their career, so they may not immediately recognize it. Additionally, these cancers can appear in unusual organs, tissues, or cell types, and their symptoms are often vague or resemble those of more common conditions. For these reasons, rare cancers are often diagnosed at an advanced stage.

Treatment options for rare cancers are limited because pharmaceutical companies may not invest heavily in developing drugs for them since the small patient population makes clinical trials difficult and the market small. Consequently, many patients rely on treatments designed for more common cancers that might not be as effective.

Many individuals diagnosed with a rare cancer face challenges accessing expert care because knowledge about rare cancers is concentrated in a few specialized centers that are often far from where patients live. This means people may need to travel long distances, or even across countries, to find doctors who are familiar with their condition. This adds financial and emotional strain.

Another challenge patients with rare cancers often face is emotional and social isolation. Unlike common cancers, which often have large patient communities, rare cancers leave people struggling to find others with the same diagnosis, making them feel alone and unsupported. Patients and their families may lack access to reliable information about their diagnosis, support groups, and advocacy organizations, which increases stress and uncertainty.

Rare Cancer Day was created by the Rare Cancer Coalition, a program under the National Organization for Rare Diseases (NORD) composed of member organizations focused on specific rare cancers. The day’s main goal is to highlight the challenges people with rare cancers and their families and caregivers face. It also aims to advocate for research and funding to improve early detection and treatment.