Cancer is a disease that can affect people in different ways. For some, the first sign of cancer may be pain or discomfort. But for others, cancer may develop without causing any noticeable symptoms. So can some cancers really be painless? Let’s take a closer look at this important question.
What is cancer pain?
Cancer pain results from the disease itself or its treatment. Tumors can press on nerves, bones, organs, and other tissues, causing pain. Or cancer treatments like surgery, chemotherapy, and radiation can also cause pain. Cancer pain can range from mild to severe and may be acute (short-term) or chronic (long-lasting).
Common causes of cancer pain
- The tumor itself – pressing on organs, nerves, or bone
- Cancer spreading to the bones
- Nerve and tissue damage from surgery
- Mucositis and inflammation from chemotherapy or radiation
- Medications and their side effects
So cancer pain is very common. But it’s important to understand that not all cancers automatically cause pain. Some cancers can grow quite large before causing symptoms. And some cancer types are less likely than others to be painful.
Are some cancers truly painless?
Yes, some cancers are painless and do not have any noticeable symptoms. This is more common with certain cancer types and early-stage cancers. Let’s look at some examples of potentially painless cancers:
Early-stage prostate cancer
Prostate cancer is very common in men. In its early stages, most prostate cancers grow slowly and do not cause symptoms. As the cancer advances, it can start to cause urinary symptoms like difficulty urinating. But early prostate cancer is often detected through screening before any symptoms develop.
Pancreatic neuroendocrine tumors
These rare pancreatic cancers tend to grow slowly and often do not cause pain or other problems for many years. As a result, they are sometimes found incidentally through imaging tests for other issues.
Low-grade tumors
Some low-grade cancerous tumors, like certain types of gastrointestinal stromal tumors (GISTs), grow very slowly. They often do not cause any pain or discomfort, even as they get bigger. Low-grade tumors are less aggressive and invasive than high-grade cancers.
Blood cancers
Cancers like leukemia, lymphoma, and myeloma affect the blood and bone marrow. In their early stages, these blood cancers may not cause symptoms. As they progress, symptoms like fatigue, fever, and unusual bleeding/bruising can develop.
Early-stage melanoma
Melanoma is a serious skin cancer. When caught early, it typically appears as an unusual mole or skin lesion. An early-stage melanoma usually does not cause pain. But more advanced melanomas can be painful.
Why would cancers be painless?
There are a few reasons why some cancers may not initially cause pain or other symptoms:
- The cancer is slow-growing and not invading/damaging nearby tissues.
- The tumor is small and contained within an organ, without affecting other structures.
- The cancer is in a part of the body with fewer pain-sensing nerves (like the pancreas).
- The tumor is not located near any major nerves or organs.
- The cancer spreads in a subtle way that does not irritate nerves or cause obstruction/blockages.
Blood cancers like leukemia also often lack painful symptoms because they don’t form solid tumors. And some skin cancers only affect the outermost layers of skin initially.
How are silent cancers detected?
Since painless cancers do not have symptoms that lead to early diagnosis, how are they detected? Here are some ways silent cancers are often discovered:
Screening exams
Some cancers can be detected early through regular screening even before symptoms develop. Examples include mammograms to screen for breast cancer, PSA blood tests for prostate cancer, and colonoscopies to check for colorectal cancer.
Imaging tests
Many people today get scans like CT scans, MRIs, and ultrasounds for various health issues. These imaging tests can incidentally catch cancers that haven’t caused symptoms.
Blood tests
General blood work done for medical exams can sometimes reveal early cancers. Elevated tumor marker levels or abnormal blood cell counts can prompt further testing like scans and biopsies.
Biopsy
Sometimes a suspicious lump or area is biopsied even without definite symptoms. This can diagnose early cancers, like a small tumor in the breast or thyroid.
Should screening be done for silent cancers?
Since some cancers don’t have obvious symptoms initially, screening exams play an important role in early detection. Screening refers to testing for cancer in healthy people without symptoms. Examples include:
- Mammograms for breast cancer
- Colonoscopy for colorectal cancer
- Pap smears for cervical cancer
- PSA blood tests for prostate cancer
- Low-dose CT scans for lung cancer
Catching cancers early through screening often leads to better outcomes. But screening also has limitations and risks. For example, false positive results can lead to unnecessary follow-up procedures and anxiety. Discussing the pros and cons of screening with your doctor can help determine appropriate options based on your age, risk factors, and preferences.
Current general screening guidelines
| Cancer Type | Screening Test | Starting Age | Frequency |
|---|---|---|---|
| Breast Cancer | Mammogram | 40-45 years | Every 1-2 years |
| Colon Cancer | Colonoscopy | 45 years | Every 10 years |
| Cervical Cancer | Pap smear | 21 years | Every 3-5 years |
| Lung Cancer | Low-dose CT scan | 50-80 years (if smoker) | Every year |
| Prostate Cancer | PSA blood test | 50 years | Every 1-4 years |
Screening tests and schedules are continually updated based on new research. Talk to your doctor about current recommendations.
Are painful cancers more dangerous?
It’s a common assumption that painful cancers must be more advanced or dangerous than non-painful ones. But this isn’t necessarily true. Here are some important points:
- Some aggressive high-grade cancers are fast growing but don’t hurt initially. Examples are pancreatic cancer and aggressive brain tumors.
- Meanwhile, some slow-growing low-grade tumors can be painful if located near nerves or if they ulcerate.
- Cancers that spread to the bones often cause pain, but this does not mean they are untreatable.
- The degree of pain depends on each person’s pain tolerance and nerves involved, not just the cancer type.
- Early-stage treatable cancers can cause pain if they damage tissues and press on nerves.
So some very treatable cancers cause early pain, while some dangerous cancers grow silently. The presence or absence of pain does not always correlate with cancer aggressiveness or stage.
When should silent cancers be treated?
Asymptomatic early cancers often raise the question – should they even be treated right away if they aren’t causing problems? There are pros and cons to consider:
Potential benefits of early treatment
- Stop cancer growth and prevent it from becoming advanced and symptomatic
- Higher chance for a cure with early-stage cancer treatment
- Prevent cancer metastases and spread
- Peace of mind knowing the cancer is being addressed
Possible downsides of early treatment
- Overdiagnosis and overtreatment of non-harmful cancers
- Side effects and complications from treatments undergone unnecessarily
- Anxiety and reduced quality of life due to prolonged treatment
- Higher medical costs for early vs delayed treatment
As with cancer screening, the decision to treat silent early cancers involves balancing risks versus rewards. Your doctor can help determine if watchful waiting or early treatment is preferable based on your specific cancer, expected prognosis, age, health status, and personal preferences.
Can silent cancers turn painful later?
Yes, cancers that lack symptoms initially can sometimes become painful later as they grow and advance. Here are some examples:
Prostate cancer
Early prostate cancer usually does not cause pain. But if left untreated, it may eventually spread to the bones and cause bone pain.
Pancreatic cancer
Pancreatic cancer typically lacks early symptoms. But over time it can cause abdominal or back pain as it invades surrounding nerves and organs.
Brain tumors
Some slow-growing brain tumors don’t hurt at first. But increased intracranial pressure, headaches, seizures, and neurological deficits can occur as they get larger.
Lymphoma
Early-stage lymphomas may not have overt symptoms. Eventually lymph node swelling, night sweats, and enlarged organs can lead to pain.
That’s why follow-up and monitoring are important even for symptom-free cancers. New pain or concerning symptoms should prompt reevaluation.
Conclusion
While some cancers are clearly painful from early on, others can grow quietly without causing symptoms for some time. But an absence of pain does not necessarily mean cancer is less advanced or lower risk. Silent cancers are often detected incidentally or through screening. Working with your doctor for appropriate screening, follow-up of abnormal findings, and prompt evaluation of any new symptoms can help identify and treat cancers in their early stages when outcomes are often best.