In most cases, the tumour develops slowly from a polyp, a benign growth in the lining of the colon that may become cancerous over time. This process usually takes between five and ten years, providing an opportunity for early detection and prevention.

Early diagnosis is essential because it allows the disease to be identified at an early stage, when the chances of successful treatment are highest.

Symptoms

In its early stages, colorectal cancer often causes no symptoms. For this reason, it is frequently considered a silent disease.

When symptoms do occur, the most common include:

• Blood in the stool.
• Persistent changes in bowel habits, such as newly developed diarrhoea or constipation.
• Alternating diarrhoea and constipation.
• Persistent abdominal pain.
• A feeling of incomplete bowel emptying after going to the toilet (tenesmus), especially in rectal cancer.

These symptoms do not always indicate cancer, as they may also be associated with benign conditions such as haemorrhoids or anal fissures. However, if they persist for several weeks, it is important to consult a healthcare professional.

Who is affected?

There is no single cause of colorectal cancer. The disease results from a combination of genetic, environmental and lifestyle-related factors.

The main risk factors include:

• Age, particularly from 45 years onwards.
• A family history of polyps or colorectal cancer.
• Certain inherited genetic conditions.
• A diet low in fibre.
• High consumption of red and processed meat.
• Physical inactivity.

Although maintaining a healthy lifestyle may help reduce the risk of developing the disease, genetic factors play an important role and, in some cases, colorectal cancer can occur despite following these recommendations.

Diagnosis

The main test used to diagnose colorectal cancer is a colonoscopy.

This procedure allows the entire colon and rectum to be examined using a flexible tube fitted with a camera. During the examination, it is possible to:

• Detect polyps or other abnormalities.
• Remove polyps.
• Take biopsies of suspicious lesions.

To ensure the examination can be carried out properly, the bowel must be prepared beforehand with a specific diet and bowel cleansing.

Following diagnosis, additional tests are performed to determine the extent of the disease and plan the most appropriate treatment.

What role do polyps play?

Most colorectal cancers develop from a polyp.

Polyps are abnormal growths in the lining of the bowel that are initially benign. Over time, some may accumulate genetic changes and become malignant tumours.

Because this transformation is usually slow, detecting and removing polyps during a colonoscopy is one of the most effective ways to prevent colorectal cancer.

Usual treatment

Treatment depends on the location of the tumour, its stage and the characteristics of each patient.

Surgery

Surgery is the main treatment for colon and rectal cancer. Depending on the individual case, treatment may include:

• Local excision for very early-stage tumours.
• Removal of the affected section of the colon or rectum together with the nearby lymph nodes.
• Minimally invasive surgery using laparoscopy or robotic surgery.

For rectal tumours, robotic surgery using the Da Vinci Surgical System offers significant advantages by providing greater precision in an anatomically complex area.

Chemotherapy

Chemotherapy is used in selected patients to reduce the risk of recurrence.

In colon cancer, it is usually given after surgery when the characteristics of the tumour indicate a high risk of recurrence.

Radiotherapy

Radiotherapy is a key component of treatment for locally advanced rectal cancer and is usually combined with chemotherapy before surgery.

This approach has improved treatment outcomes and reduced the risk of recurrence.

Immunotherapy

In a small group of patients with very specific molecular characteristics, immunotherapy can produce such a favourable response that, in some cases, surgery may be avoided.

Follow-up

After treatment, patients attend regular follow-up appointments to detect any recurrence at an early stage and monitor their recovery.

Follow-up may include:

• Blood tests.
• Imaging tests, such as CT scans.
• Surveillance colonoscopies.
• Appointments with different specialists.

At Vall d'Hebron, follow-up also includes the assessment of possible functional sequelae, particularly after treatment for rectal cancer, as well as psychological support for both patients and their families whenever needed.

Prevention

Although not all cases of colorectal cancer can be prevented, adopting healthy lifestyle habits can help reduce the risk.

Recommendations include:

• Eating a diet rich in fibre.
• Prioritising fruit, vegetables, pulses and wholegrains.
• Limiting the consumption of red and processed meat.
• Taking regular physical activity.
• Maintaining a healthy weight.

The main preventive measure remains early detection through population screening programmes.

Screening and early detection

In Catalonia, population screening programmes are available for people aged between 45 and 74 years.

The most commonly used test is the faecal occult blood test (FOBT). If the result is positive, a colonoscopy is arranged to identify the cause.

A positive result does not necessarily mean cancer is present. In many cases, haemorrhoids or polyps are detected and can be removed before they develop into cancer.

People with a family history of colorectal cancer may need to begin screening before the recommended age. In these cases, follow-up is tailored according to family history and individual risk.

Hepatocellular carcinoma is one of the cancers with the highest mortality rate, being the third leading cause of cancer-related death.

Symptoms

In early stages, the disease is asymptomatic, meaning there are no clinical manifestations. In advanced stages, some of the following symptoms may appear:

• Abdominal pain or tenderness
• Abdominal enlargement (ascites)
• Yellowing of the skin or eyes (jaundice)
• Tendency to bleed or form bruises
• Unexplained weight loss

Who does the disease affect?

In more than 80% of cases, hepatocellular carcinoma occurs in patients with underlying liver disease, especially liver cirrhosis.

Diagnosis

Screening is important for diagnosing the disease at early stages, which is the ideal time to apply curative-intent treatment.

The diagnostic tests and procedures used depend on the patient profile:

• Patients at risk with known liver disease: Screening should be performed every six months using ultrasound. If a nodule is detected, contrast imaging tests such as CT scan or contrast-enhanced MRI are performed to confirm the diagnosis. In some cases, a liver biopsy is required, which involves extracting tumor tissue.
• Patients with unknown predisposing factors and not in a screening program: Usually diagnosed after the appearance of initial symptoms, using the following diagnostic tests:
  • Imaging tests such as CT scans and MRI
  • Tumor biopsy to extract liver tissue for histopathological examination

Usual treatment

Treatment for hepatocellular carcinoma varies for each patient, depending on tumor burden, liver function, and overall health status.

The most commonly used treatments are:

• Surgical: Resection surgery and liver transplantation, applicable in early stages
• Locoregional: Aimed at destroying tumor cells through direct ablation (radiofrequency ablation, microwave ablation, cryoablation, etc.) or via endovascular methods (transarterial chemoembolization or radioembolization)
• Systemic: Used mainly in advanced stages, currently including immunotherapy drugs and tyrosine kinase inhibitors

Survival in advanced stages has improved significantly thanks to the successful results of treatment combinations that include immunotherapy. Many patients have benefited and continue to benefit from these treatments before their official approval and commercialization through participation in clinical trials.

Most common tests

The most common diagnostic tests for this condition are ultrasound, CT scan, contrast-enhanced MRI, and biopsy. Blood tests are also used both for diagnosis and follow-up in daily clinical practice.

Prevention

The best way to prevent hepatocellular carcinoma is to avoid risk factors, such as alcohol consumption and smoking, control diabetes (a key component of metabolic syndrome associated with fatty liver disease), and prevent or treat hepatitis B and C infections.