NewsPublic figure
What John Kruk's Story Can Help Us Understand About Testicular Cancer
The Phillies star was treated for testicular cancer in 1994 and returned to play. Here is what that diagnosis means, explained calmly and simply.
A plain-language summary based on public reporting and trusted sources, linked below.
Please note: this page is educational only — it is not medical advice, and it does not speculate about anyone’s health beyond reliable public reporting. For questions about your own health, talk with your healthcare team.
Thirty-five days
The Society for American Baseball Research documents the timeline, drawing on newspaper reporting from the time. John Kruk was diagnosed with testicular cancer on March 7, 1994. His right testicle was removed the next day.
He then had 18 rounds of radiation, five days a week. On April 11, 1994, the Phillies' home opener, he played. He had received his 16th round of radiation that morning. He finished the course later that week.
Thirty-five days from diagnosis to a major league lineup. The speed of that is not a story about toughness. It is a story about what this particular cancer is like.
The disease in numbers
Testicular cancer is uncommon and highly treatable. The American Cancer Society projects about 9,810 new cases and 630 deaths in the United States in 2026, and SEER publishes that figure. Roughly 0.4 percent of men will be diagnosed with it in their lifetime.
Five-year relative survival is 94.6 percent for people diagnosed from 2016 to 2022. It is the most common cancer in men aged roughly 15 to 45, which means it arrives at an age when almost nobody is expecting it.
Those are group figures. They describe a population, not a person, and they say nothing about any individual's stage or tumor type.
What to look for
NCI lists these signs:
- a painless lump or swelling in either testicle.
- a change in how the testicle feels.
- a dull ache in the lower abdomen or the groin.
- a sudden build-up of fluid in the scrotum.
- pain or discomfort in a testicle or the scrotum.
The first item is the one that gets missed. Painless is not reassuring here. It is the classic presentation. A firm lump on the body of the testicle, found in the shower and ignored because it does not hurt, is the exact scenario doctors describe.
A monthly self-check takes under a minute, best done after a warm shower when the scrotum is relaxed. Roll each testicle between thumb and fingers and note anything hard, fixed, or new. Our guide to testicular cancer symptoms has more detail.
Why the testicle comes out first
Most cancers are diagnosed by biopsy, then treated. Testicular cancer is different, and the reason is worth understanding.
Doctors do not take a needle biopsy through the scrotum, because that can spread tumor cells into new tissue planes. Instead, NCI describes an inguinal orchiectomy: removal of the testicle through an incision in the groin. That single operation both makes the diagnosis and removes the tumor.
Before it, an ultrasound of the scrotum and blood tests for tumor markers guide the decision. This is why Kruk's surgery happened the day after his diagnosis rather than weeks later.
Two types, two paths
Germ cell tumors of the testicle are grouped as seminoma or nonseminoma. The distinction drives everything afterward, because seminomas are unusually sensitive to radiation and nonseminomas are managed differently.
Kruk's course, with radiation over several weeks after surgery, matches how a seminoma was commonly treated in 1994.
What changed since 1994
That is no longer the automatic next step, and NCI's health-professional summary is direct about why.
For stage I seminoma, NCI states that the cure rate approaches 100 percent whether or not additional treatment is given after the orchiectomy. One listed option is surveillance: no radiation to the lymph nodes at all, and instead a schedule of chest X-rays and CT scans of the abdomen and pelvis, typically every four months for three years, every six months for three more, then yearly for four more.
Across more than 1,200 patients with stage I seminoma managed this way, NCI reports an overall 10-year recurrence rate of 15 to 20 percent, with relapses treatable when they occur.
The reason to prefer watching is long-term harm. NCI cites a series of 992 men treated between 1982 and 1992 in which cardiac events were about 2.5 times higher after radiation or chemotherapy than after surveillance. The actuarial risk of a cardiac event was 7.2 percent after radiation and 1.4 percent after surveillance. Treating less, when treating less is safe, is itself a result.
Fertility, and the years after
Any man facing treatment for this cancer should be offered sperm banking before it starts. Chemotherapy and radiation can both affect fertility, and the window closes once treatment begins.
Follow-up runs for a decade, tracking markers, scans, and the late effects of whatever was given. Our page on survivorship covers that long tail.
When to make the appointment
Book within a week for any painless lump or firmness in a testicle, any change in size or texture, or a heavy, aching feeling in the scrotum or groin that lasts. Go sooner if a testicle swells suddenly.
Sudden severe testicular pain is a separate emergency, not this. It needs same-day care. Our overview of testicular cancer explains what the first appointment involves.
What this does not mean
- Most testicular lumps are not cancer. Cysts and fluid collections are common.
- A 1994 treatment plan is not today's. Surveillance replaced routine radiation for many men with early seminoma.
- Losing a testicle does not, by itself, end fertility or hormone function. Those questions are answered case by case.
- High survival figures for a group are not a promise to an individual. Stage and tumor type matter.
Sources
- SABR: April 11, 1994 — John Kruk plays first game for Phillies since cancer surgery
- NCI: Testicular Cancer Symptoms
- NCI: Testicular Cancer Treatment (PDQ) — Patient Version
- NCI: Testicular Cancer Treatment (PDQ) — Health Professional Version
- SEER Cancer Stat Facts: Testicular Cancer
How this page was made
An AI-assisted editorial system helped prepare this page. This article has not been reviewed by a healthcare professional unless a named reviewer is specifically shown. Cancer Explained is published by the National Cancer Information Foundation as a nonprofit-oriented public-interest education project. It is not a diagnostic service, does not recommend treatments, and is not for emergencies.
Found an error, a broken source link, outdated information, or wording that feels insensitive? Report it here — we log and act on material corrections.
Know someone who needs this?
Plenty of people are looking for something like this and do not know where to start. If this would help a friend or someone you love, send it on — we have written an opening line so you do not have to stare at an empty message. You can change every word of it.
Your message is written and sent in your own email or messaging app — we never see who you send it to, and nothing is added to any list.
Put the story in context
Prevention, possible warning signs, screening, and diagnosis
This story relates to Testicular cancer. The information below is general: it does not reveal anything else about a public person’s health, and not every point applies to every cancer. Personal advice depends on age, symptoms, family history, exposures, and medical history.
Prevention and risk reduction
Not every cancer can be prevented. Avoiding tobacco, protecting skin from ultraviolet radiation, limiting alcohol, staying active, and receiving recommended HPV or hepatitis B vaccination can lower the risk of certain cancers. A risk factor is not a prediction or a cause in one individual.
Symptoms and possible early signs
Possible signs vary and are often caused by conditions other than cancer. Changes worth discussing include a new lump, unexplained bleeding or weight loss, a persistent cough, lasting bowel or bladder changes, a changing skin spot, or symptoms that persist or worsen. Some early cancers cause no symptoms.
Screening and early detection
Screening looks for certain cancers before symptoms begin. Recommended tests exist only for some cancers and depend on age and risk. Screening can have benefits and harms; it is not the same as evaluating a new symptom, and there is no single routine scan or blood test that reliably screens for every cancer.
How cancer is diagnosed
Diagnosis may involve a history and exam, imaging, laboratory tests, and often a biopsy. Pathology can identify the cancer type and may test biomarkers that guide treatment. Symptoms, screening results, tumor markers, or online stories alone cannot confirm cancer.
Learn about this story’s cancer topic
A public story may encourage questions, but it should not be used to estimate your risk or choose testing. Contact a healthcare professional about a persistent or concerning change. Seek urgent care for severe or rapidly worsening symptoms.