The Orphan Drug Act incentivizes rare-cancer treatments

A law for diseases too small to pay for

The Orphan Drug Act became law on January 4, 1983. Its formal name is Public Law 97-414. The law itself explains why Congress wrote it. Some diseases affect so few people that a drug maker can expect to lose money on any treatment it develops. Congress called those treatments orphan drugs. Very few were being made.

The law changed the arithmetic. A company can ask the FDA to grant a drug orphan drug designation for a rare disease. The FDA lists what designation brings: a tax credit for the cost of testing the drug in people, a waiver of the review fee that is now close to $3 million, and up to seven years of market exclusivity once the drug is approved. The 1983 law also set up a grant program that helps pay for the testing itself.

The FDA counts a disease as rare if it affects fewer than 200,000 people in the United States. Most cancers clear that bar. NCI's rare tumor network reports that rare cancers make up about a quarter of all cancer cases.

One point gets lost in the shorthand. Designation is not approval. A designated drug still has to show that it is safe and that it works, in the same FDA review every other drug goes through.

Why a rare cancer is harder to find

Soft tissue sarcoma shows the problem well. Sarcoma is cancer that starts in the tissues that connect, support or surround other parts of the body: muscle, fat, tendon, nerve, blood vessel. The American Cancer Society projects about 13,910 new US cases of soft tissue cancer in 2026, which is 0.7% of all cancer, and SEER carries that count.

NCI describes the usual first sign as a painless lump under the skin, most often on an arm or a leg. A sarcoma that starts deep in the belly may cause nothing at all until it is large enough to press on an organ or a nerve, and then the symptom is pain or trouble breathing.

Most lumps are not cancer. But a family doctor may see one sarcoma in a career, so the pattern is not familiar the way a breast lump is.

Getting the name right is a treatment decision

Diagnosis is made with a biopsy, meaning a sample of the tumor removed for a pathologist to examine. NCI describes two kinds. A core needle biopsy takes tissue through a wide needle, often guided by ultrasound, CT or MRI. An incisional biopsy removes part of the lump through a small cut.

Where that needle goes matters more here than in common cancers. NCI states that planning the biopsy involves the surgeon, a radiation oncologist and an interventional radiologist together, because a badly placed biopsy track can change what surgery is possible later. NCI also states plainly that the tissue is best read by a pathologist with experience in sarcoma.

The pathologist reports two things. One is the exact subtype, which the lab confirms with tests such as immunohistochemistry, which uses antibodies to stain specific proteins, and FISH, which counts genes and chromosomes inside cells. The other is grade: low, mid or high, based on how abnormal the cells look and how fast they are dividing. Stage then combines grade with tumor size and spread. For an arm or leg tumor, 5 centimeters and 10 centimeters are the size cut points. Our guide to rare cancers and finding a specialist covers how to get to a center that sees these often.

What treatment involves

Surgery is the main treatment. NCI notes that small, low-grade tumors in the trunk, arms or legs are often treated with surgery alone. Larger or higher-grade tumors usually add radiation therapy, given before or after the operation, and sometimes drug treatment. High-grade sarcomas are harder to treat and more likely to spread.

When sarcoma does spread, it usually goes to the lung. NCI makes a point that applies to every cancer: sarcoma in the lung is still sarcoma, and it is treated as sarcoma, not as lung cancer. Our page on soft tissue sarcoma walks through the subtypes.

The 1983 law shows up here. Drugs for uncommon sarcoma subtypes exist because designation made those trials worth running. Our explainer on clinical trial phases describes how those trials are built.

What the numbers say about a group

SEER reports five-year relative survival for soft tissue cancer by how far it had spread when it was found, for cases diagnosed from 2016 to 2022. It is 83.3% when the tumor was still confined to where it started, 58.2% when it had reached nearby lymph nodes, and 17.0% once it had spread to distant parts of the body. Fifty-seven percent were found while still confined.

These are averages over past years. They describe a large population, not any one person, and they cannot account for treatments approved since those patients were diagnosed.

When to get checked

NCI lists these as reasons to have a lump looked at:

• A lump in soft tissue that is larger than a golf ball, roughly 5 centimeters
• A lump that is growing, at any size
• A lump that sits deep, under the muscle rather than just under the skin
• A lump that is painful, or one that came back after being removed before
• New belly pain, swelling, or trouble breathing that has no clear cause

Most lumps meeting these descriptions turn out to be harmless. Having one imaged before it is cut out is what keeps the rare one from being handled badly.

What this does not mean

• Orphan drug designation is a financial incentive, not evidence. It says nothing about whether a drug works.
• The seven-year exclusivity applies to that drug for that rare disease. It does not block other drugs for the same disease.
• Fewer than 200,000 people is the current FDA threshold. The 1983 statute has been amended several times since, including its tax credit.
• The sarcoma figures here describe soft tissue cancer as a whole. Individual subtypes behave very differently from each other.
• Nothing here is a reason to delay having a lump examined.

Sources

• Orphan Drug Act, Public Law 97-414, 96 Stat. 2049 (January 4, 1983), govinfo — https://www.govinfo.gov/content/pkg/STATUTE-96/pdf/STATUTE-96-Pg2049.pdf
• FDA, Rare Diseases at FDA — https://www.fda.gov/patients/rare-diseases-fda
• NCI, Pediatric and Adult Rare Tumor Network (MyPART) — https://www.cancer.gov/pediatric-adult-rare-tumor
• NCI PDQ, Soft Tissue Sarcoma Treatment (Patient Version) — https://www.cancer.gov/types/soft-tissue-sarcoma/patient/adult-soft-tissue-treatment-pdq
• SEER Cancer Stat Facts, Soft Tissue Including Heart Cancer — https://seer.cancer.gov/statfacts/html/soft.html

How this article was prepared

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

The National Cancer Information Foundation publishes Cancer Explained. This page is for learning. It is not medical advice and does not suggest a test or treatment.

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