Podcast Summary: "Why Are So Many Young People Getting Cancer?"

Chasing Life with Dr. Sanjay Gupta, CNN Podcasts
Date: October 10, 2025
Guest: Dr. Kimmie Ng, Gastrointestinal Oncologist, Dana Farber Cancer Center

Overview

In this episode, Dr. Sanjay Gupta explores the troubling trend of rising cancer rates among young adults, particularly colorectal cancer. Joined by Dr. Kimmie Ng, one of the nation’s leading experts in gastrointestinal cancers and founder of a center dedicated to young adults with colorectal cancer, the conversation examines why these cancers are spiking in people in their 20s, 30s, and 40s, possible causes, the importance of screening, and practical advice for prevention and early detection.

Key Discussion Points & Insights

The Alarming Rise in Young-Onset Cancers

• Historical context:
  Breast cancer, once a disease people didn’t talk about, is now more openly discussed. However, cancers are increasingly being diagnosed in younger people, including those with no risk factors or family history.

  • “More and more young people, people in their 40s, 30s, even 20s, are being diagnosed with cancers that used to be incredibly rare at those ages.” (A, 00:31)

• Colorectal cancer specifics:

  • Now the 2nd leading cause of cancer death for women under 50; projected to become #1 by 2030 (A, 00:42)
  • Often presents at an advanced stage (Stage 4), even in fit, healthy, young individuals (B, 01:13)

• Wider trend:

  • Other gastrointestinal (GI) cancers and endometrial cancer are also rising in young people (B, 14:44)

Definitions and Data

• Early or Young-Onset Cancer:
  • Typically defined as diagnosis under the age of 50, a threshold originally set because screening historically began at 50 (B, 04:26)
• Incidence & Demographics:
  • Colorectal cancer incidence is rising globally but most rapidly in Westernized, high socioeconomic status countries like Australia, New Zealand, Norway, and the UK (B, 05:58)
  • Rates in the U.S. are rising by 2–3% per year among people under 50, affecting both men and women (B, 05:00)

Quote:

• “A person born in 1990 now has quadrupled the risk of developing rectal cancer and over double the risk of developing colon cancer compared to a similarly aged person born in 1950.” (B, 07:18)

The Search for Causes

• Genes vs. Environment:
  • The rise is too rapid to be explained by genetics alone.
  • All young cancer patients should receive genetic testing, as some hereditary syndromes may be present (B, 08:23)
• Potential Environmental Factors:
  • Obesity: Leading hypothesis due to the parallel rise of obesity and young adult cancer rates. Obesity impacts inflammation, hormone signaling, and the gut microbiome, all possible contributors to cancer risk (B, 10:25)
  • Diet & Lifestyle: Diets high in red meats, processed foods, and sugar; sedentary behavior; sugar-sweetened beverages (B, 11:08)
  • Microbiome: Early life exposures may alter gut bacteria, potentially laying groundwork for future cancer risk (B, 13:32)

Memorable moment:

• “Most [young patients] are not obese. Many are marathon runners, they're triathletes, they're eating really healthy—and yet they're still being diagnosed.” (B, 11:27)

Early Life Exposures & The Microbiome

• Possibility that risk originates early:
  • Early life microbiome composition may predispose individuals. Example: certain strains of E. coli in childhood linked to DNA-damaging toxins (colibactin) (B, 13:32)
• Research challenge:
  • Longitudinal cohort studies needed, but are logistically and financially difficult (B, 12:11)

Screening and Prevention

• Screening Age Recommendations:
  • Current recommendation: Begin screening at age 45 for those at average risk; consider earlier if there’s family history (B, 25:14)
• Screening Methods:
  • Colonoscopy (10-year interval if normal), stool-based tests (yearly or every 3 years depending on the test type), and virtual (CT) colonography (B, 25:14–26:49)
• Effectiveness:
  • Even a single colonoscopy can significantly reduce lifetime risk (B, 19:53)
• Screening Gaps:
  • Only 25% of people ages 45–49 are currently getting screened; even over age 50, rates are just 66% (B, 20:27)

Quote:

• “The best screening test is the one that actually gets done.” (B, 25:14)

Barriers & Stigma

• Stigma:
  • Discomfort around discussing bowels and stool hinders awareness and screening, similar to past breast cancer stigma (B, 21:38)
  • Racial and ethnic disparities: Non-Hispanic Black populations have a 20% higher incidence and 40% higher mortality, partly due to lower screening rates (B, 22:17)

Symptoms to Watch For

• Red Flags for Colorectal Cancer:
  • Blood mixed in the stool (“not just on top or toilet paper—mixed in is more characteristic of a malignant cause”) (B, 23:33)
  • Change in bowel habits (new diarrhea/constipation, thinner stools)
  • Abdominal pain
  • Fatigue/shortness of breath (suggesting anemia)
  • Unintentional weight loss (B, 23:19)

Notable quote:

• “It’s so important that we try to normalize these conversations and ask physicians to routinely and systematically ask: Are you having blood in the stool? Are you having a change in your bowel habits?” (B, 24:31)

Advice for Parents and the Next Generation

• Lifestyle recommendations:
  • Encourage a healthy lifestyle in children: balanced diet, activity, avoiding smoking and alcohol (B, 27:33)
  • Open family communication about symptoms destigmatizes the topic—“awareness and lack of hesitation to talk about symptoms… is so important.” (B, 27:55)

Notable Quotes & Memorable Moments

• On the dramatic shift:
  • “It was shocking to see that a young person, perfectly fit and healthy, no risk factors, no family history, could be diagnosed with stage four disease.” (B, 01:13)
• On research challenges:
  • “In an ideal world, we would study people from in utero to infancy, through childhood, and then follow them until they receive a diagnosis of cancer... but a study like that is really not feasible.” (B, 12:11)
• On prevention messaging:
  • “Screening is nothing compared to actually having to undergo treatment for a cancer.” (B, 19:53)
• On parent-to-child advice:
  • “Be open and honest about what might be happening and what symptoms they might be experiencing… I think that’s so important, that awareness and that lack of hesitation...” (B, 27:55)

Timestamps for Key Segments

• Rising trend in young cancers, Dr. Gupta personal reflection: 00:02 – 01:26
• Definition and data on early-onset cancers: 04:20 – 05:54
• Birth cohort effect and hypotheses: 06:57 – 08:55
• Genetics vs environment, insights on testing: 08:23 – 10:57
• Microbiome and early life risk factors: 12:11 – 14:28
• Other rising GI and endometrial cancers: 14:44 – 15:38
• Screening recommendations and challenges: 17:01 – 21:03, 25:14–26:49
• Symptoms and public health: 23:19 – 24:47
• Parental advice and child's health: 27:19 – 28:14

Takeaways & Actionable Advice

• Begin colorectal cancer screening at age 45; earlier if you have a family history.
• Talk openly with family and physicians about digestive and stool-related symptoms.
• Maintain a healthy lifestyle from childhood onward: diet, exercise, avoid smoking/alcohol.
• Pay attention to symptoms: blood in stool, change in bowel habits, unexplained weight loss, abdominal pain, anemia.
• Advocate for and participate in screening, especially in communities with historically lower screening rates.

Final Thoughts

This episode highlights a worrisome and not yet fully understood increase in cancers among young adults, underscoring the urgency of screening, open communication, and more research into early life and environmental factors. Listeners are empowered with practical advice and encouraged to help reduce stigma by sharing knowledge and talking about what can otherwise feel like uncomfortable topics.

For more information and resources, visit the Young-Onset Colorectal Cancer Center website (link in show notes).