Treatments

treatments

Surgery | Radiation Therapy | Chemotherapy | Immunotherapy | Targeted Therapy | Hormone Therapy | Stem Cell Therapy

Surgery

Overview. Surgery is one of the earliest cancer treatment modalities, with its origins dating back to the early 20th century. It involves the physical removal of cancerous tissue, often along with a margin of surrounding healthy tissue to ensure complete excision. Traditional open surgery requires a single large incision, while minimally invasive techniques employ small incisions to insert a camera and specialized surgical tools, resulting in less trauma to the body and faster recovery times.

Application. Surgery is most effective for localized solid tumors that have not metastasized. Its primary goal is to achieve complete tumor removal (curative intent). In cases where the tumor cannot be entirely removed, surgery may be used to debulk the tumor, reducing its size to alleviate symptoms or facilitate the efficacy of other treatments like chemotherapy or radiation. Surgery is also commonly used as an adjuvant therapy, in conjunction with other treatments, to increase the chances of eradicating the disease. Surgery plays a crucial role not only in treatment but also in the diagnosis and staging of cancer. Pathological examination of the obtained tissue samples and/or regional lymph nodes can confirm a cancer diagnosis, determine the cancer type, staging, and identify specific molecular markers that guide personalized treatment plans.

Side Effects and Risks. The invasive nature of surgery makes side effects common and variable depending on the procedure and tumor location. These may include:

Pain and discomfort at the surgical site.
Swelling, bruising, and bleeding.
Infections, necessitating prophylactic or post-operative antibiotics.
Fatigue due to the body’s recovery process.
Functional impairments (e.g., changes in digestion, urinary, or respiratory functions), especially for surgeries involving the gastrointestinal or thoracic regions.
Scarring or cosmetic changes, which may affect a patient’s psychological well-being.
Lymphedema (swelling due to buildup of lymph fluid between skin and muscle), particularly if lymph nodes are removed during surgery.

Post-surgical recovery often includes pain management strategies such as opioids or non-opioid analgesics, physical rehabilitation to restore function, and psychosocial support to address emotional challenges.

Despite its effectiveness, cancer surgery carries inherent risks and challenges, which must be carefully weighed against its potential benefits.

Anesthesia Complications.
Incomplete Resection.
Tumors in hard-to-reach areas increase the risks of surgery.
Additional conditions like diabetes, obesity, and cardiovascular disease increase the risks of surgery.

Radiation Therapy

Overview. The discovery of X-rays and radiation by Wilhelm Rontgen and Henri Becquerel in the late 19th century revolutionized medicine, introducing powerful tools for both diagnosis and treatment. While low-dose radiation provides diagnostic imaging, high-dose radiation delivered to localized tumor sites has become a cornerstone of cancer therapy due to its ability to destroy cancer cells. Its primary goal is to achieve complete tumor removal (curative intent). In cases where cure is not possible, radiation therapy can be used to relieve symptoms, improve quality of life, and reduce complications from advanced cancers.

Mechanism of Action. Radiation therapy works by inducing DNA damage in cancer cells, ultimately triggering apoptosis, a form of programmed cell death. To maximize DNA damage while minimizing harm to healthy cells, patients undergo multiple treatment sessions. Two primary types of radiation therapy are employed:

External Beam Radiation Therapy: A machine delivers radiation precisely to the tumor from various angles, ensuring targeted damage.
Internal Radiation Therapy: This method involves placing a radiation source within or near the tumor.
- Brachytherapy: Solid radioactive material, such as seeds or capsules, are implanted near the tumor site.
- Internal Radiation Therapy: Liquid radioactive substances are administered into the bloodstream to target cancer cells throughout the body.

Modern developments in radiation therapy have significantly enhanced its precision and safety, allowing for more effective cancer control while reducing damage to surrounding healthy tissue. Here are a few key advancements:

Intensity-Modulated Radiation Therapy (IMRT): IMRT uses advanced computer algorithms to modulate the intensity of radiation beams, tailoring the dose to the shape of the tumor. This precision minimizes radiation exposure to surrounding healthy tissues and is particularly beneficial for irregularly shaped tumors or those located near critical organs (e.g., spinal cord or brainstem).
Stereotactic Body Radiation Therapy (SBRT): SBRT delivers highly focused, high-dose radiation over fewer treatment sessions.
Proton Therapy: Proton beam therapy uses charged particles (protons) instead of traditional X-rays. Protons release most of their energy directly at the tumor site, resulting in minimal exit radiation and sparing surrounding tissues.
Image-Guided Radiation Therapy (IGRT): IGRT employs imaging before each radiation delivery to increase accuracy and precision.

Radiation therapy is rarely a standalone treatment. It is often integrated into a broader, multidisciplinary care plan to improve outcomes.

Side effects and Risks. While radiation therapy is effective in killing cancer cells, it can also damage nearby healthy cells, leading to side effects that vary depending on the treatment site.

General Side Effects: Skin irritation or burns at the treatment site and systemic fatigue.
Site-Specific:
- Head and Neck: Mouth sores, dry mouth, and difficulty swallowing.
- Chest: Cough and shortness of breath.
- Abdomen: Nausea and diarrhea.
- Pelvis: Bladder irritation and infertility.

Radiation therapy also carries long-term risks, such as the potential development of secondary cancers due to radiation exposure. In internal radiation therapy, precautions must be taken to minimize radiation exposure to others, as body fluids or implanted sources may emit radiation temporarily.

Chemotherapy

Overview. The term “chemotherapy” was coined by the German scientist Paul Ehrlich and referred to the chemical treatment of any disease. Alongside radiation therapy, chemotherapy is one of the most effective and widely used treatments for various cancer types. Unlike surgery, which targets a localized tumor, chemotherapy is a systemic treatment that affects the entire body. This systemic nature is particularly beneficial for treating cancers that have metastasized (spread to other organs).

Mechanism of Action. Chemotherapy primarily targets rapidly dividing cancer cells by interfering with their process of cell division, particularly during DNA replication, where the duplication of DNA occurs. DNA replication is a critical step in cell division, and any errors or damage during this process often trigger programmed cell death, known as apoptosis. This prevents the generation of daughter cells with damaged DNA. Chemotherapy induces apoptosis through two primary mechanisms:

Direct Interaction: Agents directly interact with DNA introducing DNA damage to prevent proper replication.
Indirect Interaction: Agents interfere with enzymes and pathways that are essential for a seamless DNA replication.

Common Chemotherapeutic Agent	Mechanism of Action
Alkylating Agents: Carboplatin, Chlorambucil, Cyclophosphamide, Cisplatin, Melphalan, Mechlorethamine	Damage DNA to prevent cell replication.
Antimetabolites: 5-Fluorouracil (5-FU), Cytarabine, Fludarabine, Gemcitabine, Hydroxyurea, Methotrexate	Mimic the building blocks of DNA and RNA to stop cancer cells from replicating.
Anti-Tumor Antibiotics: Bleomycin, Daunorubicin, Doxorubicin, Mitomycin C	Bind to DNA, causing DNA damage which inhibits replication.
Plant Alkaloids or Topoisomerase Inhibitors: Docetaxel, Etoposide, Irinotecan, Paclitaxel, Topotecan, Vincristine, Vinblastine	Prevent topoisomerase enzymes from unwinding DNA during replication, leading to DNA damage.
Nitrosoureas: Carmustine, lomustine, Nimustine, Semustine, Streptozotocin	Slow down or stop enzymes that help repair DNA
Corticosteroids: Dexamethasone, Hydrocortisone	Natural hormones and hormone-like drugs that block hormones to stimulate the growth of hormone-dependent tumors.

Chemotherapy can be used at various stages of cancer treatment:

Neoadjuvant Therapy: Administered before surgery to shrink tumors and improve surgical outcomes.
Adjuvant Therapy: Given after surgery to eliminate residual cancer cells and reduce recurrence risk.
Primary Therapy: Used as the main treatment when surgery or radiation is not viable (e.g., metastatic or inoperable cancers).

Common routes of administration include intravenous (IV) infusion, oral pills, injections, or topical applications for localized cancers like skin cancer. Corticosteroids are often prescribed alongside chemotherapy to help manage the side effects of cancer treatment and to reduce inflammation and pain.

Side Effects and Risks. While chemotherapy effectively targets cancer cells due to their abnormally high growth rates, it also affects healthy, fast-dividing cells, such as those in the gastrointestinal tract, hair follicles, skin, and bone marrow. This explains many of its common side effects:

Bone Marrow Suppression (Myelosuppression)
- Anemia: Reduced red blood cell count, leading to fatigue and weakness.
- Neutropenia: Reduced neutrophil count, increasing infection risk.
- Thrombocytopenia: Reduced platelet count, heightening the risk of bruising or bleeding.
Gastrointestinal Effects
- Nausea and vomiting.
- Loss of appetite or taste changes.
- Mouth sores (mucositis).
Dermatological and Hair-Related Effects
- Hair loss (alopecia).
- Skin rashes or sensitivity.
Neurological Effects
- Numbness, tingling, or pain in extremities (Peripheral Neuropathy).
- Cognitive changes, often referred to as “chemo brain,” involving memory, attention, and focus difficulties.
Reproductive and Fertility Issues
- Chemotherapy can damage sperm or eggs, causing temporary or permanent infertility.
Other Possible Side Effects
- Increased risk of secondary malignancies (rare).

Although chemotherapy is highly effective, it is accompanied by a wide range of potential side effects and long-term risks, including secondary cancers or organ damage. These considerations should be discussed in the context of their impact on the patient’s quality of life, ensuring that treatment decisions balance effectiveness with overall well-being. Additionally, drug resistance is a concert that may occur over time due to the ability of cancer cells to adapt and develop resistance mechanisms.

Immunotherapy

Overview. Immunotherapy is a cancer treatment that harnesses the body’s immune system to identify and destroy cancer cells. Unlike traditional treatments that directly target the tumor, immunotherapy works by enhancing or reprogramming the immune system to recognize cancer cells as a threat. Immunotherapy can be delivered through various approaches, such as immune checkpoint inhibitors, CAR-T cell therapy, and cancer vaccines.

Mechanism of Action. The mechanism of immunotherapy involves mobilizing the immune system to combat cancer. As part of its normal function, the immune system detects and destroys abnormal cells and can prevent or curb the growth of many cancers. Evidence of this is seen in immune cells found in and around tumors, known as tumor-infiltrating lymphocytes (TILs). The presence of TILs indicates an immune response to the tumor, and individuals with TIL-rich tumors tend to have better outcomes compared to those whose tumors lack these immune cells. However, cancer cells have evolved mechanisms to evade immune detection and destruction.

Genetic changes that make them less visible to the immune system
Express proteins on their surface that deactivate immune cells
Manipulate the surrounding normal cells to inhibit immune responses.

Immunotherapy works by overcoming these defenses, enhancing the immune system’s ability to recognize and attack cancer cells effectively.

Type of Immunotherapy	Mechanism of Action
Immune checkpoint inhibitors	Block the “off switches” that cancer cells use to evade T cells.
CAR-T cell therapy	Reprogramming of patients own T cells to target specific cancer antigens.
Monoclonal antibodies	Lab designed antibodies meant to recognize specific targets on the cancer cells and activate the immune system.
Cancer vaccines and immune system modulators	Primes the immune system to detect cancer cells more effectively.

Side Effects and Risks. While immunotherapy has revolutionized cancer care, it is associated with unique side effects, collectively known as immune-related adverse events (irAEs). These occur when an overactive immune response inadvertently targets healthy cells. Common side effects include fatigue, skin rashes, diarrhea, and flu-like symptoms. More serious risks involve inflammation in organs such as the lungs (pneumonitis), liver (hepatitis), or thyroid gland, potentially leading to life-threatening complications. The onset of these side effects can vary, requiring close monitoring and prompt management by healthcare providers. Despite immunotherapy being a breakthrough in cancer treatment achievements, only a small percentage of patients benefit from this treatment due to cancer cells developing resistance mechanisms.

Targeted Therapy

Overview. Targeted therapy is a type of cancer treatment that focuses on specific molecules involved in the growth, cell division, and spread of cancer cells. This new approach is based on our knowledge about the DNA changes and proteins drive cancer. Unlike traditional chemotherapy, which affects both healthy and cancerous cells, targeted therapy aims to block the biological processes or pathways unique to cancer cells, minimizing damage to normal cells. This approach has been used to treat various cancers, including breast, lung, and blood cancers. Targeted therapies are often used in combination with other treatments, such as chemotherapy or immunotherapy, to enhance effectiveness.

Mechanism of Action. Targeted therapy works by interfering with specific molecules or pathways critical for cancer cell survival and proliferation. Depending on the drug, it may:

Mark cancer cells to promote immune recognition or help boost your immune system to work better against cancer.
Block signals that promote cancer cell growth and division.
Prevent the formation of new blood vessels (angiogenesis) that supply tumors with nutrients.
Target proteins on the surface or inside cancer cells to deliver cell-killing substances such as toxins, chemotherapy drugs, or radiation.
Induce programmed cell death in cancer cells.
Starve cancer cells of hormones necessary for cell growth.

These therapies are often tailored based on genetic or molecular testing of the patient’s tumor, also called biomarker testing, to identify actionable targets.

Most targeted therapies are either small-molecule drugs or monoclonal antibodies.

Small-molecule drugs – able to enter cells and interfere with targets from the inside.
Monoclonal antibodies – proteins produced in the lab, that are designed to attach to specific targets found on the surface of cancer cells. Some monoclonal antibodies mark cancer cells so that they will be better seen and destroyed by the immune system. Other monoclonal antibodies directly stop cancer cells from growing or cause them to self-destruct. Still others carry toxins to cancer cells.

Side Effects and Risks. While targeted therapies tend to have fewer side effects than traditional chemotherapy, they are not without risks. Common side effects include:

Fatigue and gastrointestinal issues, such as diarrhea or nausea.
Skin reactions, such as rash or sensitivity.
Liver or kidney toxicity in some cases.
Development of resistance, where cancer cells adapt and become less responsive to treatment.

Rare but serious side effects include blood clotting disorders, heart problems, or severe allergic reactions. Monitoring and personalized adjustments in therapy are key to managing these risks and optimizing patient outcomes.

Hormone Therapy

Overview. Hormone therapy is a type of cancer treatment designed to slow or stop the growth of cancers that rely on hormones to grow. Commonly used in breast (estrogen-dependent) and prostate cancers (testosterone-dependent), hormone therapy works by interfering with the body’s hormone production or blocking the action of hormones on cancer cells. It can be administered as a standalone treatment or in combination with other therapies like surgery, radiation, or chemotherapy.

Mechanism of Action. The mechanism of hormone therapy varies depending on the type of cancer and the specific treatment used. For breast cancer, therapies often focus on estrogen, a hormone that can promote tumor growth. Drugs like selective estrogen receptor modulators (SERMs), aromatase inhibitors, or estrogen receptor antagonists work by blocking estrogen’s effect or reducing its production. In prostate cancer, hormone therapy targets androgens, such as testosterone, which are critical for prostate cancer cell proliferation. Androgen deprivation therapy (ADT) reduces androgen levels or prevents these hormones from interacting with their receptors on cancer cells, effectively slowing cancer progression.

Side Effects and Risks. While hormone therapy can be highly effective, it is not without side effects. Common side effects depend on the specific therapy but may include hot flashes, fatigue, mood changes, and reduced sexual function. Long-term use may lead to more serious risks, such as osteoporosis, cardiovascular issues, or an increased risk of certain secondary cancers. For women undergoing hormone therapy for breast cancer, there may be a higher likelihood of blood clots or uterine cancer with some treatments. It is crucial for patients to work closely with their healthcare team to monitor and manage these risks while undergoing therapy.

Stem Cell Transplant

Overview. Stem cell transplant is a procedure used to treat certain cancers, particularly blood cancers like leukemia, lymphoma, and multiple myeloma. It involves replacing damaged or destroyed blood stem cells with healthy stem cells capable of producing new blood cells. These stem cells can come from the patient (autologous transplant) or a donor (allogeneic transplant). Stem cell transplants are typically used after high-dose chemotherapy or radiation to restore the bone marrow’s ability to produce blood cells. Blood-forming stem cells grow into different types of blood cells. The main types of blood cells are:

White blood cells – part of your immune system that helps your body fight infection
Red blood cells – carry oxygen throughout your body
Platelets – help the blood clot and prevent bleeding

Mechanism of Action. The primary goal of a stem cell transplant is to regenerate healthy blood-forming stem cells and restore the body’s ability to produce essential blood cells. In an autologous transplant, stem cells are collected from the patient before undergoing aggressive cancer treatment, then reintroduced to help recovery. In an allogeneic transplant, stem cells from a compatible donor are infused, and these cells replace the damaged bone marrow. Donor stem cells can also provide a “graft-versus-tumor” effect, where the donor immune cells help fight residual cancer cells. Stem cells may be collected either from the blood, called peripheral blood stem cell transplant (PBSCT), or from the bone marrow, called bone marrow transplant (BMT).

To decide if the stem cells from a donor are a match for a host, they will be tested for their human leukocyte antigens (HLA). HLAs are sets of proteins, or markers, that are present on most cells in the body. Each person has a different set of HLAs. The more HLAs that the host and the donor have in common, the better the chance that the body will accept the donor’s stem cells. Most often, the best match for an allogeneic stem cell transplant is a sibling.

Side Effects and Risks. While stem cell transplants can be lifesaving, they carry significant risks and side effects. Common side effects include fatigue, nausea, and low blood cell counts, which can increase the risk of infections, anemia, and bleeding. Long-term or severe risks include:

Graft-versus-host disease (GVHD) in allogeneic transplants, where donor cells attack the recipient’s body.
Organ damage, such as to the liver or heart.
Secondary cancers due to the intensive treatments used before transplantation.
Fertility issues or hormone imbalances.

Careful matching, ongoing monitoring, and supportive therapies help manage these risks and improve outcomes for patients undergoing stem cell transplants.

Reviewed. 01/2025