Rare cancers, explained

The 1-in-5 paradox

Rare and less common cancers make up about a fifth of Australian diagnoses and over 30% of cancer deaths, yet receive only a small share of dedicated research funding.

Little commercial incentive

Large drug trials are expensive, so companies rarely run them for small patient groups. Many rare cancers have no approved or PBS-listed targeted treatment.

Borrowed treatment plans

Without their own trials, rare cancers are often treated with plans designed for common cancers — which can mean low response rates and avoidable side effects.

Small, scattered patient groups

Patients are spread across Australia and the world, making it hard to recruit enough people for trials without registries and international collaboration.

Late diagnosis and missed targets

Rare cancers are often diagnosed late. Without genomic testing at diagnosis, treatable changes (such as HER2, KRAS, BRAF or FGFR) may only be found after standard treatment has failed.

A different disease

Mucinous ovarian cancer is biologically unlike the common high-grade serous type and is genetically closer to bowel and other gastrointestinal cancers.

Many subtypes

Expansile and infiltrative growth patterns, borderline-associated tumours, and cancers that spread from the appendix or bowel can all look alike — accurate pathology is essential.

The mucin shield

Thick mucin (MUC2, MUC5AC and others) physically blocks chemotherapy and hides cancer cells from immune cells, creating an "immune-cold" tumour.

Standard chemo often fails

In advanced disease, carboplatin + paclitaxel responds in only a small minority of patients, so many need different or targeted approaches.

Different mutations, different patients

HER2/ERBB2 amplification (about 15–20%), KRAS mutations (about 40–60%), TP53 changes and CDKN2A loss vary between patients — one treatment does not fit all.

Young patients

The disease can affect teenagers and young women, where fertility-sparing surgery and fast access to genomic testing matter greatly.

Mucinases (Stanford)

Engineered enzymes that cut away the mucin coat, potentially letting immune cells and targeted drugs reach the cancer.

Surgery + HIPEC and BromAc

Cytoreductive surgery with heated chemotherapy, and BromAc (Prof. David Morris, Sydney) — a mucin-dissolving treatment in clinical trials.

Mucinous ovarian carcinoma in four teenage girls with fatal outcomes

Frontiers in Oncology, 2026

Case series of four young patients — the basis of Research cases 11–14 on this site.

Mucinous ovarian cancer: a review

PubMed Central (PMC4261626)

Peer-reviewed overview of diagnosis, biology and treatment challenges.

Bioengineered tool unmasks cancer cells

Stanford University, 2023

Engineered mucinase enzymes strip the protective mucin coat from cancer cells so the immune system can see them.

NCI clinical trials search

US National Cancer Institute

International trials, including rare-cancer studies open to overseas patients.