CRC + Lung Cancer

Why is preventive testing for lung and colorectal(CRC) cancer important?

Lung and colorectal cancer are among the most common and serious oncological diseases. Both diseases have a high mortality rate if diagnosed only in advanced stages. Yet timely diagnosis can significantly increase the chances of successful treatment and long-term survival. Medicine today can perform miracles in this regard.

Lung cancer is often asymptomatic in its early stages, which complicates its early detection. Preventive screening, such as low-dose CT scans, X-rays, and ctDNA liquid biopsies, allows for the detection of tumors in the early stages when treatment is much more effective. Screening is particularly important for smokers and individuals with long-term exposure to harmful substances.

Colon cancer usually develops from polyps, which can be removed by colonoscopy before they turn into malignant tumors. Screening methods, such as the fecal occult blood test, ctDNA liquid biopsy, or the aforementioned colonoscopy, help not only in diagnosis but also in prevention. Unfortunately, many people avoid colonoscopy and postpone the examination until they experience symptoms.

Key benefits of preventive testing using the ctDNA Liquid Biopsy method:
•. Early detection: Increases the chances of complete recovery.
• Prevention: Removing precancerous lesions reduces the risk of developing cancer.
• Lower treatment costs: Early-stage cancer is less demanding to treat than advanced-stage cancer.

Investing in regular testing is an investment in health. Talk to your doctor about appropriate preventive screening – it could save your life.

Learn more about our integrated Lung+Colorectal cancer ctDNA Liquid biopsy test.

Colorectal cancer (CRC)

Definition and Prevalence
- Colorectal cancer originates in the colon or rectum, parts of the large intestine.
- It is one of the most common cancers worldwide and a leading cause of cancer-related deaths.
- Most colorectal cancers begin as benign polyps that can transform into malignant tumors over time.
Risk Factors
- Age: Risk increases significantly after age 50.
- Family History/Genetics: Familial adenomatous polyposis (FAP), Lynch syndrome, or a strong family history of CRC.
- Lifestyle: Diet high in red/processed meats, low fiber, obesity, physical inactivity, smoking, and heavy alcohol use.
- Inflammatory Bowel Disease: Long-standing ulcerative colitis or Crohn’s disease increases risk.
Symptoms
- Changes in bowel habits (diarrhea, constipation)
- Blood in stool or rectal bleeding
- Abdominal pain or cramping
- Unexplained weight loss or fatigue
- Iron-deficiency anemia (especially in right-sided colon cancers)

Disease Progression

Adenoma-Carcinoma Sequence
- Most CRCs develop from pre-cancerous polyps (adenomas) over many years.
- As polyps grow and accumulate genetic mutations, they may progress to localized cancer.
Local Invasion and Spread
- Cancer invades through the colon/rectal wall into surrounding tissues.
- Lymphatic Spread: Cancer cells may spread to regional lymph nodes.
- Distant Metastasis: Advanced stages may spread to the liver, lungs, peritoneum, or other organs, often via the bloodstream or lymphatics.

Screening*

Importance of Screening
- Early detection and removal of polyps can prevent progression to cancer.
- Screening decreases both incidence and mortality from colorectal cancer.
Screening Modalities
- Colonoscopy: Gold standard; allows for direct visualization, biopsy, and removal of polyps. Recommended every 10 years for average-risk individuals starting at age 45–50, based on guidelines.
- Fecal Tests:
  - Fecal Immunochemical Test (FIT) or Fecal Occult Blood Test (FOBT) detect hidden blood in stool. Recommended annually or biennially.
  - Stool DNA Test: Combines FIT with DNA analysis for abnormal cells, recommended every 3 years in some guidelines.
- Flexible Sigmoidoscopy: Visualizes the distal colon; may be used in combination with FIT.
- CT Colonography (Virtual Colonoscopy): An alternative screening tool when colonoscopy isn’t possible.
High-Risk Populations
- Individuals with a family history of CRC, known genetic syndromes, or personal history of polyps may require earlier and more frequent screening.

Treatment Approaches

Treatment is guided by the stage of cancer, location, molecular characteristics, and patient health.

Localized Disease (Stages I–III)

Surgical Resection
- Primary treatment for non-metastatic CRC is surgery to remove the tumor and nearby lymph nodes.
- Types of surgery:
  - Colectomy: Removal of a portion of the colon.
  - Proctectomy: For rectal cancer, removal of part or all of the rectum.
  - Minimally invasive (laparoscopic/robotic) approaches are common.
Adjuvant Therapy
- Chemotherapy: Often recommended after surgery, especially for stage III and high-risk stage II colon cancers to eliminate microscopic disease.
- Radiation Therapy: Commonly used in rectal cancer, often with chemotherapy (chemoradiation) before surgery (neoadjuvant) or after surgery (adjuvant) to reduce recurrence.

Advanced/Metastatic Disease (Stage IV)

Systemic Chemotherapy
Targeted Therapy
Immunotherapy
Palliative Care

Summary

Colorectal cancer is a common yet preventable and treatable malignancy with established screening methods that reduce mortality. Early detection through colonoscopy and other screening tests can catch precancerous polyps and early-stage cancers, leading to more favorable outcomes. Treatment varies by stage, ranging from surgical resection with adjuvant therapy in early stages to systemic chemotherapy, targeted therapies, and immunotherapy for advanced disease. Prognosis is heavily dependent on stage at diagnosis and tumor biology, but advances in treatment continue to improve survival and quality of life for many patients.

Lung cancer

Definition and Prevalence
- Lung cancer originates in the tissues of the lungs, often in the cells lining the air passages.
- It is one of the most common cancers globally and the leading cause of cancer-related deaths.
- The two main types are:
  - Non-Small Cell Lung Cancer (NSCLC): Accounts for ~85% of cases. Subtypes include adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.
  - Small Cell Lung Cancer (SCLC): Comprises ~15% of cases, known for its aggressive nature and rapid spread.
Risk Factors
- Smoking: The primary risk factor, contributing to the majority of cases.
- Environmental Exposures: Radon gas, asbestos, air pollution, and occupational carcinogens.
- Genetics: Family history of lung cancer can increase risk.
- Other Factors: History of lung diseases such as COPD or previous lung scarring.

Disease Progression

Local Growth
- Lung cancers often start as small nodules or localized masses.
- NSCLC tends to grow more slowly than SCLC; however, both can invade nearby tissues such as the chest wall, diaphragm, or mediastinum.
Lymphatic and Vascular Spread
- Cancer cells can migrate to nearby lymph nodes, particularly the hilar and mediastinal nodes.
- They may also invade blood vessels, leading to distant metastases.
Distant Metastases
- Common metastatic sites include the brain, bones, liver, and adrenal glands.
- SCLC is particularly known for early, widespread metastasis, while NSCLC may remain localized longer.

Screening*

Screening Recommendations
- Low-Dose Computed Tomography (LDCT): Recommended annually for high-risk individuals (ages 55–80 years, with at least a 30 pack-year smoking history, and who currently smoke or have quit within the past 15 years).
- Exclusion Criteria: Individuals with a low risk of lung cancer, limited life expectancy, or significant comorbid conditions typically are not screened.
Purpose of Screening
- Early detection through LDCT can identify lung nodules before symptoms arise, improving the chances of successful treatment and survival.

Treatment Approaches

Non-Small Cell Lung Cancer (NSCLC)

Localized (Stages I–II)
- Surgery: Lobectomy or pneumonectomy, often with lymph node dissection, is the primary treatment.
- Adjuvant Therapy: May include chemotherapy or radiotherapy post-surgery to reduce recurrence risk.
Locally Advanced (Stage III)
- Often treated with a combination of chemoradiation and sometimes surgery, depending on tumor size, location, and patient health.
Advanced/Metastatic (Stage IV)
- Systemic Therapies:
  - Chemotherapy
  - Targeted Therapy: For patients with specific genetic mutations
  - Immunotherapy
- Radiation Therapy: Used for local control, palliation, or treating brain metastases (e.g., stereotactic radiosurgery).

Small Cell Lung Cancer (SCLC)

Limited Stage
- Combination chemotherapy (commonly etoposide with cisplatin or carboplatin) plus concurrent radiation therapy is the standard.
- Prophylactic Cranial Irradiation (PCI) may be offered to reduce brain metastases risk after initial therapy.
Extensive Stage
- Primarily treated with combination chemotherapy and, more recently, immunotherapy (e.g., atezolizumab or durvalumab combined with chemotherapy) to improve survival.
- Radiation therapy may be used palliatively.
Relapsed or Refractory Disease
- Options include second-line chemotherapy agents (topotecan) and supportive/palliative care.

Summary

Lung cancer remains a leading cause of cancer mortality, but advances in screening, surgical techniques, targeted therapies, and immunotherapies have begun to improve outcomes, particularly for subsets of patients with actionable mutations or those eligible for immune-based treatments. Early detection through low-dose CT scans in high-risk populations can significantly improve survival by catching the disease at a more treatable stage. Prognosis largely depends on the type of lung cancer (NSCLC vs. SCLC), stage at diagnosis, molecular features, and how well the cancer responds to treatment.

*Please note that screening programs may vary among different countries.