Targeted Cancer Therapy - Precision Cancer Treatment
Targeted cancer therapy blocks the specific gene change or protein that drives a cancer, such as EGFR or ALK in lung cancer, HER2 in breast cancer or BCR-ABL in leukemia, mostly with tablets taken at home. Matched to the right marker, it works far better than unselected treatment. Our oncologists test the tumor first, choose the drug, manage side effects and follow you once you are back home.
About This Department
Chemotherapy attacks every fast-dividing cell. Targeted therapy aims at the one fault that drives a particular cancer.
Targeted cancer therapy, also called precision cancer treatment, uses drugs designed to block a specific gene change or protein that a cancer depends on, such as an EGFR or ALK mutation in lung cancer, HER2 in breast cancer or BCR-ABL in chronic myeloid leukemia. Patients take most of them as tablets at home, and others as antibodies by drip. When the drug matches the target, the results are striking. Among patients with chronic myeloid leukemia who started imatinib, 83.3 percent were alive ten years later (Hochhaus and colleagues, New England Journal of Medicine, 2017), and across 570 trials covering 32,149 patients, matching the drug to a biomarker tripled the response rate compared with treatment not matched to one (Schwaederle and colleagues, 2015). Everything depends on finding the target first, through tumor testing. This page explains how targeted therapy differs from chemotherapy and immunotherapy, the main drug families, how the target is found, the cancers treated this way, resistance, side effects, taking tablets at home, and how patients from abroad arrange treatment at Biruni Hospital in Istanbul.
What targeted therapy is
How it differs from other treatments
Targeted therapy works only when the target is present. That is why testing comes before treatment.
| Treatment | How it works | Who it suits |
|---|---|---|
| Chemotherapy | Kills dividing cells, cancerous or not | Most cancers, with or without a target |
| Targeted therapy | Blocks a specific driver protein in the cancer | Cancers carrying that target |
| Immunotherapy | Releases the immune system to attack the cancer | Cancers the immune system can recognize, guided by markers such as PD-L1 and MSI |
Kinds of targeted drug
| Family | How it works | Examples |
|---|---|---|
| Kinase inhibitors, tablets | Block growth-signal enzymes inside the cell | Osimertinib, alectinib, imatinib, dabrafenib |
| Monoclonal antibodies, drip | Block a receptor on the cell surface | Trastuzumab, cetuximab, bevacizumab |
| Antibody-drug conjugates, drip | Antibody carrying chemotherapy to the cancer cell | Trastuzumab deruxtecan, sacituzumab govitecan |
| PARP inhibitors, tablets | Exploit faulty DNA repair, as in BRCA mutations | Olaparib, niraparib |
| CDK4/6 inhibitors, tablets | Stop hormone-driven breast cancer cells dividing | Palbociclib, ribociclib, abemaciclib |
| Blood cancer targets, tablets | Block BTK, BCL2 or other survival signals | Ibrutinib, venetoclax |
Names ending in -nib are small-molecule tablets. Names ending in -mab are antibodies.
Finding the target
Why matching matters
Across malignancies, a personalized strategy was an independent predictor of better outcomes and fewer toxic deaths, and nonpersonalized targeted therapies were associated with significantly poorer outcomes than cytotoxic agents (Schwaederle and colleagues, Journal of Clinical Oncology, 2015).
| Measure | Matched to a biomarker | Not matched |
|---|---|---|
| Median response rate | 31 percent | 10.5 percent |
| Median time before growth | 5.9 months | 2.7 months |
| Median survival | 13.7 months | 8.9 months |
| Treatment-related deaths | 1.5 percent | 2.3 percent |
Precision is not a guarantee
Not every tumor has a target.
In lung adenocarcinoma, well over half of patients carry a gene change with a matched drug, in pancreatic cancer only a small minority, and in many cancers the answer lies in between. Even when a target is found, the evidence behind it varies, from drugs proven in large randomized trials to findings that only suggest a clinical trial. Responses to a targeted drug are sometimes dramatic, with tumors shrinking within weeks and symptoms easing within days, and in advanced disease they still end for the majority when resistance develops. Honest planning weighs all of this, and for many patients the best treatment combines a targeted drug with surgery, radiation, chemotherapy or immunotherapy.
Targeted therapy by cancer
| Cancer | Target | Drugs |
|---|---|---|
| Lung adenocarcinoma | EGFR, ALK, ROS1, BRAF, KRAS G12C, MET, RET, HER2 | Osimertinib, alectinib, lorlatinib, sotorasib and others |
| Breast cancer | HER2, hormone receptors with CDK4/6, PIK3CA, BRCA | Trastuzumab, ribociclib, alpelisib, olaparib |
| Bowel cancer | RAS wild type, BRAF V600E, HER2 | Cetuximab, panitumumab, encorafenib |
| Melanoma | BRAF V600 | Dabrafenib with trametinib |
| Ovarian and prostate cancer | BRCA and repair genes | Olaparib, niraparib |
| Kidney and liver cancer | VEGF receptors | Cabozantinib, lenvatinib |
| Gastrointestinal stromal tumor | KIT, PDGFRA | Imatinib, ripretinib |
| Chronic myeloid leukemia | BCR-ABL | Imatinib, dasatinib, nilotinib |
| Chronic lymphocytic leukemia | BTK, BCL2 | Ibrutinib, acalabrutinib, venetoclax |
Among the patients in the imatinib group, the estimated overall survival rate at 10 years was 83.3 percent, and long-term administration was not associated with unacceptable cumulative or late toxic effects (Hochhaus and colleagues, 2017).
The same drug can work in very different organs when the target is the same.
Lung cancer, the clearest example
The median progression-free survival was significantly longer with osimertinib than with standard EGFR tablets, 18.9 months against 10.2 months, with lower rates of serious adverse events, 34 percent against 45 percent (Soria and colleagues, 2018).
| Trial | Comparison | Result |
|---|---|---|
| FLAURA, EGFR | Osimertinib against gefitinib or erlotinib | Time before growth 18.9 against 10.2 months |
| CROWN, ALK | Lorlatinib against crizotinib | Alive without growth at 12 months 78 against 39 percent |
Resistance
What happens when the tablet stops working?
Resistance is the reason treatment plans include regular scans and, at progression, a repeat test.
What happens next
Side effects
- Skin rash, dry skin and nail fold infections with EGFR drugs.
- Diarrhea, the commonest shared side effect.
- High blood pressure and protein in the urine with drugs that block blood vessel growth.
| Family | Typical side effects | What helps |
|---|---|---|
| EGFR tablets | Acne-like rash, diarrhea, sore nail folds | Creams, antibiotics for the skin, loperamide |
| ALK tablets | Swelling, raised cholesterol, weight gain, mood changes | Lipid-lowering drugs, dose adjustment |
| VEGF-blocking drugs | High blood pressure, sore hands and feet, tiredness | Blood pressure tablets, skin care |
| HER2 antibodies | Rare weakening of heart muscle | Heart scans every three months |
| PARP inhibitors | Tiredness, low blood counts, nausea | Blood tests, dose adjustment |
| CDK4/6 inhibitors | Low white cell count, diarrhea | Regular counts, planned breaks |
Side effects are different from chemotherapy, often milder, and last as long as the tablet is taken. Most are managed without stopping treatment.
Taking tablets at home
| Substance | Effect | Advice |
|---|---|---|
| Grapefruit and Seville orange | Raise drug levels | Avoid during treatment |
| Stomach acid reducers | Lower absorption of some tablets | Check timing with the pharmacist |
| St John's wort and some antibiotics or antifungals | Raise or lower drug levels | Check every new medicine first |
A missed dose is usually skipped, never doubled. The instruction sheet for each drug says exactly what to do.
Living on long-term tablets
Some patients take a targeted tablet for many years.
Life goes on. Work, travel and family life continue. The routine becomes habit, with blood tests at home and scans every few months, and the oncologist adjusts the dose to keep side effects small enough to live with. Planning travel around tablet supply, time zones and blood test dates becomes part of life. Pregnancy has to be avoided on most targeted drugs.
For patients from abroad
Your coordinator
One coordinator from the international patients office handles arrangements from the first message through discharge and answers the same WhatsApp number once you are back home. The office works in English, Arabic, French, Russian, Serbian, Romanian and Spanish and books interpreters for other languages, and it arranges the visa invitation letter, airport transfers, daily transport and accommodation near the hospital. Halal, vegetarian and diabetic meals, a prayer room on site, and a female physician on request wherever the rota allows.
Cost
| Item | Included | Priced separately |
|---|---|---|
| The drug | A month of tablets, or each antibody dose | Additional months dispensed for travel |
| Monitoring | Consultation, routine blood tests | Scans, heart and eye checks |
| Testing | Review of existing results | Gene testing, biopsy |
References
- Hochhaus A, Larson RA, Guilhot F, et al. Long-term outcomes of imatinib treatment for chronic myeloid leukemia. N Engl J Med. 2017;376(10):917-927.
- Schwaederle M, Zhao M, Lee JJ, et al. Impact of precision medicine in diverse cancers. A meta-analysis of phase II clinical trials. J Clin Oncol. 2015;33(32):3817-3825.
- Soria JC, Ohe Y, Vansteenkiste J, et al. Osimertinib in untreated EGFR-mutated advanced non-small-cell lung cancer. N Engl J Med. 2018;378(2):113-125.
- Shaw AT, Bauer TM, de Marinis F, et al. First-line lorlatinib or crizotinib in advanced ALK-positive lung cancer. N Engl J Med. 2020;383(21):2018-2029.
Editor's note
Written by the Biruni Hospital medical editorial team. Reviewed by Prof. Dr. Özcan YILDIZ, Medical Oncology.
Medically reviewed by
Prof. Dr. Özcan YILDIZ
Medical Oncology
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