Cancer

Cancer results from uncontrolled growth of malignant cells, forming tumors that affect surrounding tissues and organs. Sometimes cancer cells spread to other parts of the body (metastases). Through appropriate laboratory testing, cancer can be detected at increasingly earlier stages. Earlier detection means greater chance of successful treatment with higher survival rates, better quality of life, reduced care needs, and lower costs.

In vitro diagnostics

Categorized by different types of cancer, several examples illustrate the added value of laboratory tests in detecting, diagnosing, monitoring, and treating tumors.

In vitro diagnostics

• Cervical cancer

  There is a causal relationship between cervical cancer development and persistent infection with high-risk variants of Human Papillomavirus (hrHPV). The progression from harmless infection to malignant tumor is slow and can take up to fifteen years. This period includes pre-stages that are highly treatable. Early detection is crucial to prevent tumor development.

  hrHPV test

  The molecular test detects HPV virus infection based on viral DNA. In cervical cancer screening programs, a stepwise screening approach is used. The cervical smear is first tested for hrHPV presence. If the sample is hrHPV-positive, cytological analysis is performed to assess the severity and nature of abnormal cells.

• Prostate cancer

  Annually, approximately twelve thousand men in the Netherlands are diagnosed with prostate cancer. PSA (prostate-specific antigen) is a biomarker to detect prostate cancer presence, but the PSA test is not specific. About twenty percent of men over fifty have elevated PSA values. While this could indicate prostate cancer, elevated PSA can also result from benign prostate enlargement or prostate inflammation. Nevertheless, PSA is a useful biomarker, particularly when combining three PSA-related blood values.

  Prostate Health Index (PHI)

  PSA exists in blood in both free and bound forms, along with various PSA precursors. The prostate health index (PHI test) combines test results of three different isoforms: total PSA, free PSA, and [-2]proPSA. The quotient of [-2]proPSA and free PSA multiplied by the square root of total PSA yields the PHI index. This combination test is three times more sensitive than a PSA test alone and is thus a more reliable predictor of prostate cancer.

• Colorectal cancer

  Each year in the Netherlands, approximately twelve thousand people are diagnosed with colorectal cancer, and four thousand people die from this disease. When detected early, colorectal cancer is highly treatable. Therefore, population screening began in 2014. People aged 55 to 75 are invited to participate in the screening every two years. They receive a stool test, the so-called iFOB test (immunochemical Fecal Occult Blood test). By detecting invisible blood in stool at an early stage, intestinal tumors or their precursors can be detected early.

  iFOB test

  The fecal sample collected at home is sent to the laboratory where it's examined through hemoglobin (Hb) detection. Hb presence is demonstrated based on an immunochemical reaction with Hb antibodies. A positive iFOB test result leads to an internal examination (colonoscopy) to investigate the presence of a tumor or precursors (polyps). When colorectal cancer is discovered at an early stage, the chance of cure is greater and treatment less intensive.

  Although the iFOB test is effective, work is being done on modifications to discover pre-stages and potentially malignant polyps even earlier. The so-called multitarget iFOB test measures not only hemoglobin but also the proteins calprotectin and serpine.

• Lung cancer

  Lung cancer is the third most common form of cancer after breast cancer and colorectal cancer. The incidence in the Netherlands is approximately ten thousand newly diagnosed patients annually. Most cases involve the non-small cell form of lung cancer (NSCLC), and smoking is the cause in 85 percent of cases. However, some cases of non-small cell lung carcinoma are not related to smoking but are instead caused by acquired genetic abnormalities. For example, the ALK gene mutation, a genetic change leading to excessive production of the ALK receptor tyrosine kinase protein, which causes uncontrolled cell growth. Another example is the EGFR gene mutation. Due to an abnormality in the epidermal growth factor receptor (EGFR), too many growth signals occur, causing cells to continue multiplying. Both genetic abnormalities can be detected with specific gene mutation tests.

  ALK mutation test

  In only three to five percent of all lung cancer cases is there an ALK gene mutation. For treating this small subgroup, a targeted and effective medication has been developed: crizotinib, an ALK receptor tyrosine kinase inhibitor. Using the ALK mutation test, patients who would benefit from this expensive treatment can be selected.

  The ALK mutation test detects rearrangements in the ALK gene based on fluorescence in-situ hybridization (FISH). The test is performed on prepared tumor tissue. The ALK mutation test is a so-called companion diagnostic, a combination of predictive test and medication.

  EGFR mutation test

  For patients with confirmed EGFR mutations, specific treatments are possible with tyrosine kinase inhibitors (TKIs), such as erlotinib, gefitinib, and afatinib. The EGFR mutation test can select patients who would benefit from this expensive treatment. The mutation can be demonstrated through DNA analysis of blood plasma using PCR. The EGFR mutation test is a ‘companion diagnostic’, combining predictive testing and medication.

• Bladder cancer

  In the Netherlands, over six thousand patients annually receive a bladder cancer diagnosis. In three-quarters of cases, it involves a tumor in the mucosa, a so-called superficial urothelial cell carcinoma (UCC) or non-invasive tumor. These tumors can be treated by removal through endoscopic surgery but tend to recur. It's important to detect a (recurring) bladder tumor as early as possible. This can be done with a sensitive and specific molecular test.

  FISH-test

  The molecular cytological test detects bladder cancer cells in urine based on specific DNA abnormalities in these cells on chromosomes 3, 7, and 17 and absence of the 9p21 locus. The abnormalities are visualized via fluorescence in-situ hybridization (FISH). The test is used in combination with standard diagnostic procedures in bladder cancer investigation. The test detects bladder tumors in all stages and grades.

• Melanoma

  Fifty to seventy percent of patients with skin melanoma have a mutation in the BRAF gene. Usually it's a so-called V600E mutation, but in a third of cases, it's a V600K or V600D mutation. BRAF mutations lead to formation of overactive B-Raf protein. This protein controls cell growth, and when overactive, leads to uncontrolled growth and eventually cancer. BRAF-mutated tumors are often dangerous and aggressive, and respond poorly or not at all to chemotherapy. Treatment with BRAF inhibitors, such as vemurafenib and dabrafenib, is an effective therapy.

  BRAF mutation test

  The BRAF mutation test detects V600E, V600K, and V600D mutations. The molecular test is based on DNA analysis using PCR technology and is performed on prepared tumor tissue. The test is a so-called companion diagnostic, combining predictive testing and medication. Patient selection for treatment with BRAF inhibitors is based on BRAF mutation tests.

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