Can I Sue If My Doctor Did Not Diagnose My Cancer Correctly?

 Posted on January 22, 2026 in Medical Malpractice

When you are not feeling well, you have to be able to trust your physician to diagnose your condition correctly. This includes figuring out exactly what the problem is, and prescribing the right medications or treatments. For serious conditions like cancer, early detection and proper treatment often determine whether a patient goes into remission or faces life-threatening consequences.

So what happens if your doctor does not detect your cancer or fails to diagnose it promptly? What if they attribute your symptoms to another cause and do not treat the cancer? Do you have a personal injury claim? Call Carlson Law Group, P.C. to speak with our experienced Joliet medical malpractice lawyer to see if you may qualify for compensation.

How Common Are Cancer Misdiagnosis Cases?

Cancer misdiagnosis happens more often than most people realize. According to research published in the journal BMJ Quality and Safety, almost one million Americans are permanently disabled or die from misdiagnosed diseases each year. Cancer is one of the most frequently misdiagnosed conditions because symptoms can be vague or similar to less serious illnesses.

Studies show that breast cancer, colorectal cancer, and lung cancer are among the most commonly misdiagnosed cancers:

• Women may be told their breast lumps are benign cysts when they are actually cancerous tumors.

• Patients with colon cancer may be told they have irritable bowel syndrome or hemorrhoids. 

• Lung cancer patients may be treated for pneumonia or chronic bronchitis for months before receiving the correct diagnosis.

These delays matter because cancer often spreads quickly. Stage 1 breast cancer has a five-year survival rate of nearly 100 percent according to the Breast Cancer Research Foundation. Stage 4 breast cancer, which has spread to other parts of the body, has a five-year survival rate of only about 30 percent. When a doctor fails to diagnose cancer early, patients lose their best chance for survival.

What Is a Medical Misdiagnosis?

There are several ways that a doctor can misdiagnose patients, and each can have devastating consequences.

Delayed Diagnosis

With many serious conditions, the sooner appropriate treatment begins, the better the likely prognosis. With a delayed diagnosis, the physician does make a diagnosis, but not quickly enough. A delayed diagnosis means that a patient does not receive proper treatment promptly, allowing the condition to get worse. Widespread cancers, for example, are resistant to treatments. In turn, this decreases chances of survival.

Failure to Diagnose

In this scenario, the doctor never diagnoses cancer. That means a patient never receives treatments, resulting in premature disability and death. 

Incorrect Diagnosis

Sometimes, doctors decide that a different condition is causing symptoms. A physician will likely prescribe medications and treatments that are appropriate for a condition a patient does not have. The patient may experience various harmful effects from these treatments, but is still not getting any treatment for cancer.

Is Every Misdiagnosis Grounds for a Medical Malpractice Claim?

Physicians are required to provide a high standard of care for their patients. If a misdiagnosis results from a doctor failing to meet that standard of care, a patient may qualify for compensation through a medical malpractice claim. Not every misdiagnosis makes someone eligible. These claims are based on negligence, which means failing to behave as another reasonable physician would in the same situation.

• Examples of negligence in a cancer misdiagnosis include:

• Failing to order appropriate diagnostic tests

• Misreading test results

• Disregarding or failing to investigate some patient symptoms

• Failing to obtain or review patient medical history

• Lack of thorough communication

An attorney from Carlson Law Group, P.C. can investigate a misdiagnosis and how it affected you. We will consider several factors, such as:

• Would most doctors have made the correct diagnosis promptly?

• Why did your physician make the error?

• What harm did you suffer because of the misdiagnosis?

• Did the misdiagnosis cause your condition to worsen?

• Are you facing a worse prognosis because of the misdiagnosis?

• Did your misdiagnosis create extra medical expenses, more time lost from work, and additional pain and suffering?

The answers to these and other case-specific questions will tell us whether you can pursue a medical malpractice claim. If a loved one loses their life due to misdiagnosis, you might be able to file a wrongful death action.

What Does Illinois Law Say About Medical Malpractice?

Illinois has specific laws that govern medical malpractice cases. Under the Illinois Medical Malpractice Act, which is found at 735 ILCS 5/2-622, you must prove four things to win your case.

First, you must show that the doctor owed you a duty of care. This means you had a doctor-patient relationship. Second, you must prove the doctor breached that duty by failing to meet the standard of care that other reasonable doctors would provide. Third, you must show that the breach caused your injury. Finally, you must prove you suffered actual damages, such as medical bills, lost wages, or pain and suffering.

The "standard of care" means what a reasonably careful doctor with similar training would do in the same situation. For example, if you went to your doctor complaining of persistent cough, weight loss, and chest pain, a reasonably careful doctor would likely order a chest X-ray or CT scan to rule out lung cancer. If your doctor dismissed your symptoms without ordering these tests and you later learned you had advanced lung cancer, that could be a breach of the standard of care.

How Long Do You Have to File a Medical Malpractice Claim in Illinois?

Illinois law gives you a limited time to file a medical malpractice lawsuit. You generally have two years from the date you knew or should have known about the malpractice to file your claim. This is called the "statute of limitations."

For cancer misdiagnosis cases, the clock usually starts when you discover the misdiagnosis, not when the doctor first made the mistake. For example, if your doctor failed to diagnose your breast cancer in 2024 but you did not learn about the misdiagnosis until 2026, you typically have two years from 2026 to file your lawsuit.

Because these deadlines are strict and can be complicated, you should contact a medical malpractice attorney as soon as you suspect your doctor misdiagnosed your cancer. Missing the deadline means you lose your right to compensation forever.

Request Your Free Consultation With Our Skilled Joliet, IL Medical Misdiagnosis Lawyer

Medical malpractice can alter your life, especially in cases involving a cancer misdiagnosis. The compassionate legal team from Carlson Law Group, P.C. will fight to help you get the compensation you deserve. With nearly 25 years of experience, Attorney Carlson has a long history of ensuring that at-fault parties are held accountable. 

As a former prosecutor and judge, he understands how to build strong cases and hold negligent doctors responsible. Call us at 815-710-3700 today to speak with our experienced Will County, IL personal injury attorney.