Understanding the Rising Cancer Rates Among Gen X

Recent research indicates a troubling trend: the long-standing decline in cancer rates may be reversing.

Epidemiology often begins with straightforward questions, but these inquiries can quickly become complex. For instance, is cancer more prevalent today than in the past? At first glance, this seems simple. However, the reality is that the number of new cancer diagnoses in the United States has reached unprecedented levels. Last year, around 2 million individuals received a cancer diagnosis, compared to approximately 1 million in 1990. Yet, this figure can be misleading due to the growing population. Thus, it is more insightful to consider cancer rates — specifically, cases per 100,000 people.

Even when examining cancer incidence rates, clarity is elusive. The U.S. population is older than it was in 1960, and age is a significant risk factor for most cancers. Therefore, if rates for certain cancers are rising, can we genuinely conclude that a concerning trend is at play, or is it simply a reflection of an aging population? A former professor of mine often emphasized, "the question is what is the question." To truly grasp whether cancer risk has fundamentally shifted over time, we need to analyze age-adjusted cancer rates.

However, this approach introduces another layer of complexity. Older individuals are not only older in a biological sense but also hail from earlier birth cohorts. Current 70-year-olds were exposed to various risk factors in their 40s, while today's 50-year-olds encountered the same risks when they were younger. Birth cohort effects are crucial; if a harmful carcinogen was released in 1992, for instance, it could lead to a rise in cancer rates among everyone living at that time, regardless of age.

Interestingly, cancer incidence could be better understood by examining risk across social generations rather than by calendar years. This perspective reveals a notable exception: Generation X, whose cancer rates diverge from the trend of decreasing incidence observed in preceding generations.

As a member of Generation X, born in 1979, my upbringing included carefree activities, a love for music, and a growing awareness of health issues. We were taught about cancer risk factors and encouraged to adopt healthier lifestyles, but the actual impact on cancer rates has not been as favorable as anticipated. The findings in a recent JAMA Network Open publication highlight this unsettling reality.

Researchers analyzed the SEER cancer database, which encompasses 3.8 million cancer cases in the U.S. from 1992 to 2018, spanning birth years from 1908 to 1983, covering the Greatest Generation through Generation X. The vital data points included the ages at which individuals were diagnosed with cancer and their birth years, allowing for an assessment of changes in cancer rates over time.

For instance, examining lung cancer rates at age 60 across generations reveals a clear downward trend for those born more recently.

This trend aligns with effective anti-smoking campaigns over the past several decades. However, the situation is more concerning for certain other cancers. Rates of kidney and thyroid cancers have surged among individuals born later in the century compared to their predecessors.

When considering major cancer types collectively, a consistent pattern emerges. The Greatest Generation experienced the highest cancer rates, which declined and plateaued for Baby Boomers, but then began to rise for Generation X, marking an alarming trend where we now face a higher risk of cancer than our parents did.

What could be driving this increase? There are benign explanations, such as advancements in heart disease treatment, which allow more individuals to survive long enough to face cancer diagnoses. However, it's essential to consider that this study focuses on detected new cancers — an important distinction. Technological advancements have significantly improved our ability to detect cancers earlier and identify cases that might have gone unnoticed in the past. Thyroid cancer exemplifies this trend, with a dramatic rise in diagnoses correlating with the widespread use of thyroid ultrasounds.

Supporting the notion that increased detection is a key factor, cancer mortality rates have generally declined over time. Although I may be more likely to be diagnosed with kidney cancer than my parents were, I also have a better chance of surviving it due to earlier detection and improved treatments.

On the other hand, there are concerning explanations as well. Environmental changes since the 1940s have altered the types of exposures my generation faced compared to our parents. While they contended with lead and tobacco smoke, we have encountered a different array of risks, including industrial chemicals, pesticides, and ultra-processed foods.

Ultimately, this research underscores that the battle against cancer is ongoing and evolving. From my clinical experience, I have observed younger individuals presenting with cancers that were traditionally associated with older age groups. While advancements have undoubtedly improved cancer treatment, achieving the goal of eradicating cancer will require us to adapt our strategies continually. Cancer trends are shifting rapidly, and we must keep pace.

This video titled "Why Gen X is the First Generation to Have More Cancer than Their Parents" delves into the reasons behind the rising cancer rates among Generation X, examining various contributing factors.

In another insightful video, "Gen X, millennials have greater risk of developing over a dozen cancers, research finds," researchers discuss the heightened cancer risks facing these generations, highlighting alarming trends and potential causes.