Intratumoral cancer therapy is an emerging treatment method that involves delivering therapeutic agents directly into tumors to target cancer cells more effectively with fewer side effects. This approach is gaining attention for treating various types and stages of cancer. Let’s explore the common cancers where intratumoral therapy shows promise, how it works, and what patients can expect.
What Is Intratumoral Therapy?
Intratumoral therapy means injecting cancer-fighting drugs, immunotherapies, or other agents directly into a tumor rather than giving treatment systemically (through the bloodstream). This local delivery helps concentrate the treatment at the tumor site, potentially increasing effectiveness and reducing damage to healthy tissues. The Global Intratumoral Cancer Therapy Market is experiencing robust growth, with an estimated valuation of USD 257.7 billion in 2025 and expectations to more than double by 2035, fueled by rising cancer incidence and advances in precision medicine.
This targeted treatment approach is becoming increasingly preferred due to its ability to stimulate the immune system directly within the tumor, reduce systemic toxicity, and improve patient outcomes. Several types of cancer, including lung, breast, melanoma, prostate, and head & neck cancers, are treated with intratumoral therapies. Growing adoption is further supported by technological innovations, ongoing clinical trials, and regulatory endorsements, all contributing to broadening the applicability of these therapies within oncology.
Types of Cancer Treated by Intratumoral Therapy
- Skin Cancer
Skin cancers such as basal cell carcinoma and melanoma are some of the most accessible for intratumoral injection. Treatments like Imiquimod—a topical immune response modifier—have been used effectively and are approved for certain types of skin cancers. - Breast Cancer
Intratumoral injections have been used in breast cancer to deliver immunotherapies and small-molecule drugs. By injecting directly into the tumor, the immune system can be activated precisely where it’s needed, improving local tumor control and potentially shrinking tumors before surgery. - Head and Neck Cancers
These cancers often recur locally and can be difficult to treat once advanced. Intratumoral therapy offers a way to enhance immune response against these tumors, with ongoing clinical trials investigating combinations of immune checkpoint inhibitors directly injected into tumors. - Lung Cancer
For some types of lung cancer, intratumoral treatment can be combined with other treatment forms like cryoablation (freezing cancer cells). This combination may enhance local tumor shrinkage and possibly trigger systemic immune responses affecting tumors elsewhere. - Soft Tissue Sarcomas
Because these tumors are often localized and accessible, intratumoral therapies such as immune modulators combined with other treatments have been used to attack sarcomas both at the primary site and in metastatic locations.
How Does Intratumoral Therapy Work?
The therapy aims to stimulate the body’s immune system locally, making the tumor more visible to immune cells. Agents like immune checkpoint inhibitors or toll-like receptor agonists are often used. These therapies “wake up” immune cells right inside the tumor, enabling them to attack cancer cells directly and help generate a systemic immune response that can reach other tumor sites.
Advantages of Intratumoral Therapy
- Targeted Delivery: Higher concentration of the drug at the tumor source.
- Reduced Side Effects: Lower systemic exposure means fewer side effects.
- Immune Activation: Can convert a “cold” tumor (one not recognized by the immune system) into a “hot” one that the immune system can attack.
- Combination Potential: Works well with other therapies like surgery, radiation, or systemic immunotherapy.
Final Thoughts
Intratumoral cancer therapy represents a promising advance in the fight against cancer. By delivering treatment directly into tumors, it sharpens the precision of therapy, reducing side effects and potentially improving patient outcomes. While currently used primarily for accessible tumors like skin, breast, and head and neck cancers, research continues to explore broader applications. As this therapy evolves, it may become a powerful tool in personalized cancer care.
