What cancers go undetected?

Cancer is a devastating disease that affects millions of people worldwide each year. While great advances have been made in cancer screening and treatment, many cancers still go undetected or are caught at later stages when they are harder to treat. This article will examine some of the most common cancers that often go undetected and discuss reasons why this occurs. Timely detection and diagnosis of cancer is critical for effective treatment and positive outcomes. Increased awareness of the warning signs, risk factors, and appropriate screening guidelines for various types of cancer are important steps toward detecting these diseases at earlier more treatable stages.

Table of Contents

Breast Cancer

Breast cancer is one of the most common cancers in women. According to the American Cancer Society, in 2022 there will be an estimated 287,850 new cases of invasive breast cancer diagnosed and 51,400 cases of non-invasive breast cancer in the US. Some key points about breast cancers that go undetected:

Many breast cancers are found via mammogram screening, but mammograms sometimes miss cancers or have false negatives. Tumors can be obscured by dense breast tissue on mammography.

Some women do not follow recommended breast cancer screening guidelines. The USPSTF recommends women aged 50-74 undergo mammogram screening every 2 years. However, studies show many women in this age group do not have regular screening.
Younger women aged 40-49 are more likely to have cancers missed by mammograms. The USPSTF says this age group may elect to have screening mammography but does not recommend it routinely.
Breast cancers that are faster growing, aggressive, and develop in the interval between mammogram screenings are also more likely to go undetected initially.

Symptoms such as a new lump, skin changes, nipple discharge, or skin irritation are sometimes ignored by patients or not brought to the attention of healthcare providers in a timely manner.

Routine screening mammograms, clinical breast exams, and awareness of breast cancer symptoms play an important role in early detection. Increased compliance with screening guidelines and improved breast cancer screening technology for dense breasts may help reduce missed breast cancers in the future.

Lung Cancer

Lung cancer accounts for about 13% of all new cancers and 23% of cancer deaths. Key facts about lung cancers that go undetected include:

Most people diagnosed with lung cancer do not exhibit symptoms until the cancer has spread. Only 16% of lung cancers are diagnosed at an early stage.
Currently, there are no recommended screening guidelines for lung cancer for the general population. Screening is recommended for those at high risk due to smoking history.
Low dose CT screening is recommended for older adults with a significant smoking history. However, less than 5% of eligible candidates receive this screening.

Lung cancers can develop and spread quickly between CT screening intervals before being detected.
People ignore early symptoms like coughing up blood, persistent cough, chest pain, wheezing, and weight loss.

Earlier detection of lung cancer depends on increasing awareness and screening for those at highest risk. More research is needed to develop faster, more affordable, and precise lung cancer screening techniques.

Colorectal Cancer

Colorectal cancer is one of the most preventable and treatable cancers if detected early. But many colorectal cancers still go undetected. Here are some key factors:

It is estimated that 1 in 3 adults are not up to date with recommended colorectal cancer screening.
The USPSTF recommends adults age 45-75 be screened for colorectal cancer. However only 67% are compliant with screening.

People may feel healthy and ignore symptoms like blood in stool, abdominal pain, changes in bowel movements, unexplained weight loss, and fatigue.
False negatives occur with stool based tests like high-sensitivity fecal occult blood tests (FOBT) and fecal immunochemical tests (FIT).
Even colonoscopies can sometimes miss cancers and precancerous polyps, especially if preparation is poor.

Adhering to screening guidelines, being aware of warning signs, and promptly reporting symptoms to healthcare providers allows more colorectal cancers to be found early.

Skin Cancer

Skin cancer is the most common cancer in the United States with over 5 million cases diagnosed annually. But many skin cancers go undetected initially:

Melanoma accounts for only 1% of skin cancer cases but causes a majority of skin cancer deaths due to it often being caught late.

Many people do not routinely examine their skin for changes or new growths that could indicate skin cancer.
Some don’t realize that non-healing sores, moles changing shape or color, and unusual growths could signal skin cancer.
Preventative skin cancer screenings are not typically part of routine healthcare. People must initiate visits when concerned about skin changes.

Precancers like actinic keratoses often cause no symptoms so go unseen without skin exams.

Education on performing regular self-exams and seeking dermatology evaluation of changing moles or suspicious lesions is imperative for early detection of skin cancers.

Ovarian Cancer

Ovarian cancer causes more deaths than any other cancer of the female reproductive system, primarily because it is difficult to detect early. Factors contributing to ovarian cancer going undetected include:

There are no standard recommended screening tests for ovarian cancer for average risk women.
Symptoms like bloating, pelvic pain, feeling full quickly when eating, and urinary issues are vague and often ignored.
By the time ovarian cancer causes symptoms, it has often already spread beyond the ovaries.

Ovarian cancer risk rises with age. The median age at diagnosis is 63.
Genetic mutations like BRCA1/BRCA2 raise ovarian cancer risk and warrant earlier screening.

Research on more precise ovarian cancer screening approaches is needed. Having a discussion with providers about personal risk factors can help determine if additional screening is warranted.

Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers, with a 5-year survival rate around just 11%. Contributing factors to pancreatic cancers going undetected include:

There are no recommended screening tests for the general population. Screening is only done in high risk individuals.
The pancreas is located deep within the body, so tumors cannot be seen or felt in early stages.

Symptoms do not usually appear until the cancer is advanced.
Symptoms like jaundice, abdominal pain, weight loss, nausea, and fatigue can indicate many other conditions besides cancer.
Pancreatic cancer risk rises with age, with most cases occurring after age 65.

Researchers hope to develop a reliable screening technique to detect pancreatic cancer earlier. Symptom awareness and notifying providers about risk factors like family history and genetic syndromes can potentially lead to earlier diagnosis.

Risk Factors and Warning Signs

While the reasons and risk factors for developing specific cancers are varied and complex, some shared risk factors and signs to be aware of for hidden cancers include:

Smoking – Tobacco use is linked to increased risk of lung, colorectal, pancreatic, head and neck, and other cancers.

Age – Most cancers risks increase with age, so regular age-appropriate screening is key.
Family history – Having close relatives diagnosed with certain cancers raises your risk.
Unexplained weight loss – Can signal several types of cancers.

Changes in bowel/bladder habits – May indicate colorectal, uterine, prostate, or bladder cancers.
Abdominal pain – Can be a sign of ovarian, stomach, pancreatic or liver cancers.
Fatigue/weakness – Possible marker for leukemia, colon, stomach, and ovarian cancers among others.

Unexplained fevers – Associated with blood cancers like leukemia and lymphoma.
Skin changes – Non-healing sores, new growths or moles, changes in existing moles could indicate skin cancer.

Being aware of common symptoms, even if vague, along with your personal risk factors can prompt earlier conversations with healthcare providers and cancer screening if appropriate.

Conclusion

While great progress has been made in cancer treatment over past decades, early detection still offers the best hope for positive outcomes in cancer cases. Some of the most prevalent and lethal forms of cancer like lung, colorectal, breast, ovarian, pancreatic and skin often go undetected initially. Reasons range from lack of symptoms, lack of effective screening tests for the general population, failure to follow screening guidelines, ignoring warning signs and risk factors, false negative screening results, and cancers developing aggressively between screening intervals. Increased awareness through education and more personalized risk-based screening have potential to detect more hidden cancers at earlier more treatable stages. Empowering the public with knowledge and resources to identify their risks, know appropriate screening timelines, recognize subtle symptom changes, and take prompt action for evaluation when concerned can help save lives by finding hidden cancers sooner. More research to improve early detection and develop viable population-based screening for currently untestable cancers is still critically needed. But becoming an educated and proactive participant in your healthcare provides a key first step for uncovering hidden threats early when treatment is most effective.