Hodgkin’s lymphoma (HL) is a cancer that begins in the B-lymphocytes of the lymphatic system. It is considered one of the more curable cancers, and chemotherapy serves as the primary treatment method. The total number of chemotherapy treatments is highly personalized. The specific treatment plan depends on the characteristics of the disease and how the cancer responds to the initial medications. The regimen is chosen to maximize the chance of cure while minimizing potential long-term side effects.
The Role of Disease Staging
The initial step in determining treatment is accurately staging the disease using the Ann Arbor system. This system divides the extent of the lymphoma into four main stages, denoted by Roman numerals I through IV. Stage I means the cancer is confined to a single lymph node region. Stage II involves two or more regions but remains on only one side of the diaphragm; these are grouped as “early-stage” disease.
Stage III means the lymphoma has spread to lymph node regions on both sides of the diaphragm. Stage IV indicates widespread involvement of organs outside the lymphatic system, such as the bone marrow or liver. These higher stages are termed “advanced-stage” disease. Modifiers also influence the treatment plan, including the presence of “B symptoms” (unexplained fever, night sweats, or significant weight loss) and “bulky disease” (a tumor mass greater than 10 centimeters). Early-stage cases without these risk factors are considered “favorable,” while their presence shifts the case to an “unfavorable” category, prompting more intensive treatment.
Common Chemotherapy Regimens
Standard treatment relies on combination chemotherapy protocols, which use several drugs to attack cancer cells from multiple angles. The most common regimen worldwide is ABVD, an acronym for doxorubicin, bleomycin, vinblastine, and dacarbazine. This combination is often the initial choice due to its effectiveness and manageable toxicity profile.
A more intensive regimen, typically reserved for advanced disease, is BEACOPP, which includes seven different drugs. The term “cycle” refers to a complete course of medication delivery followed by a period of rest, allowing the body to recover. For example, a single ABVD cycle spans 28 days, with drugs administered intravenously on Day 1 and Day 15. The total number of these cycles is highly individualized.
Determining the Total Number of Cycles
The total number of chemotherapy cycles is tied to the disease stage and the patient’s early response to treatment. For patients with favorable early-stage disease (Stage I or II), therapy is often limited to a shorter course, typically two cycles of the ABVD regimen. This brief chemotherapy is usually followed by involved-site radiation therapy (ISRT) directed at the original tumor locations. If radiation is omitted, the chemotherapy course may be extended to three to six cycles of ABVD alone.
Patients with unfavorable early-stage or advanced-stage disease (Stage III or IV) require a longer duration, often receiving six to eight cycles of ABVD or an intensified regimen like escalated BEACOPP. The decision regarding the full course is frequently adapted based on an interim Positron Emission Tomography (PET) scan, typically performed after the first two cycles (iPET2).
A negative iPET2 result indicates a complete metabolic response and confirms the treatment is working effectively. This favorable result allows for treatment de-escalation in many protocols. For example, doctors may stop the bleomycin component and continue with four more cycles of AVD (doxorubicin, vinblastine, and dacarbazine), totaling six cycles. Removing bleomycin reduces the risk of long-term lung toxicity.
A positive iPET2 result suggests the cancer is not responding sufficiently, requiring an escalation of therapy. In this scenario, the treatment plan is intensified by switching to a stronger regimen, such as escalated BEACOPP or a regimen including the targeted drug brentuximab vedotin. This response-adapted approach ensures that the total number of cycles and the intensity of the treatment are precisely tailored to achieve the best outcome.
Monitoring and Follow-Up After Treatment
Once the prescribed number of chemotherapy cycles is complete, the patient enters a surveillance phase. The primary goal of follow-up is to monitor for relapse, which is most likely to occur within the first five years after treatment. Visits are initially frequent, often scheduled every two to four months for the first two years, then gradually decrease.
These appointments include a physical examination, blood tests to check organ function, and surveillance imaging. Imaging tests, such as CT or PET/CT scans, are used periodically to check the original sites of the disease. This monitoring allows for the earliest possible detection of recurrence, ensuring that any necessary salvage therapy can be initiated promptly.