Hodgkin’s Lymphoma (HL) is a cancer of the lymphatic system, characterized by the presence of Reed-Sternberg cells. It is considered one of the most curable forms of cancer, and most individuals achieve long-lasting remission after successful treatment. For long-term survivors, including those 20 years post-treatment, the primary concern is whether the disease can return. While most recurrences happen early, a return of the original HL is possible decades later, though this is rare. Survivorship focuses on managing this low, persistent risk and addressing other health considerations resulting from past therapies.
Defining Late Recurrence
The risk of Hodgkin’s Lymphoma returning decreases significantly over time, with most relapses occurring within the first two to three years after initial treatment. An HL recurrence is defined as “late” if it occurs five or more years after achieving complete remission. For a survivor 20 years out, the probability of the original disease returning is small but measurable.
Studies show that the cumulative incidence of late recurrence (LR) is estimated between 5.4% and 6.9% at 20 years post-diagnosis. This low percentage reflects the success of modern treatment regimens in eliminating cancer cells. LR suggests that a small population of malignant cells may have remained dormant for an extended period, reactivating years later.
In some cases, the late recurrence may be a new, distinct lymphoid malignancy rather than a true return of the original HL. Patients with nodular lymphocyte-predominant Hodgkin Lymphoma (NLPHL) have a higher risk of late recurrence compared to those with classical HL. While sustained remission substantially reduces the risk, it does not eliminate the possibility of a late-stage return.
Secondary Cancers Resulting from Treatment
A more significant concern for survivors 20 years after treatment is the development of a secondary malignant neoplasm (SMN). This new cancer arises as a long-term consequence of the initial radiation or chemotherapy used for treatment, not from the original HL. The risk of developing an SMN often surpasses the risk of a true HL recurrence two decades later. The 20-year risk of developing any secondary cancer is approximately 20%, depending on the specific treatments received.
Secondary cancers result from the DNA-damaging effects of the treatments. Radiation therapy, especially older techniques using higher doses, is associated with the later development of solid tumors. Solid cancers like lung, breast, and thyroid cancers often arise years or decades after initial radiation exposure. For women who received radiation to the chest, the risk of breast cancer is markedly increased, often appearing 20 years earlier than in the general population.
Chemotherapy agents, particularly alkylating agents, are linked to an increased risk of secondary blood cancers, including acute myeloid leukemia (AML) and non-Hodgkin Lymphoma (NHL). The relative risk of developing NHL can be more than 20 times higher than in the general population for HL survivors. The risk of solid tumors, such as lung and gastrointestinal cancers, remains elevated for at least 40 years after radiation therapy, necessitating lifelong surveillance.
Symptoms and Signs of Potential Return
Long-term survivors should be aware of physical changes that could signal a return of the disease or the emergence of a secondary cancer. Symptoms of a late recurrence often mirror those experienced during the initial diagnosis. A recognizable sign is the painless swelling of lymph nodes, particularly in the neck, armpit, or groin.
Systemic symptoms, known as B symptoms, warrant immediate medical investigation. These include unexplained, persistent fevers, drenching night sweats, and unintentional weight loss of more than ten percent of body weight over six months. Other concerning signs include persistent fatigue not relieved by rest and generalized itching without a rash.
These symptoms can be vague and may be caused by common, non-cancerous conditions. However, for an HL survivor, any persistent or recurring symptom requires prompt evaluation by a healthcare provider familiar with the patient’s history. Early detection of a recurrence or a new malignancy offers the best opportunity for successful intervention.
Long-Term Follow-Up and Surveillance
A comprehensive approach to long-term medical follow-up is necessary due to the persistent risk of both late recurrence and secondary cancers. Survivors should establish a personalized Survivorship Care Plan detailing their original diagnosis, treatment history, and recommended surveillance schedule. Follow-up visits are recommended at least once a year after the initial five-year monitoring period concludes.
Enhanced screenings are recommended based on the type of treatment received. Women who received chest radiation are advised to begin breast cancer screening earlier and more frequently than the general population, starting 8 to 10 years after treatment or at age 40, whichever is sooner. This screening often includes both annual mammography and breast magnetic resonance imaging (MRI).
Regular monitoring of heart function, blood pressure, and cholesterol levels is essential due to the heightened risk of cardiovascular disease from chest radiation and certain chemotherapies. Survivors who received neck radiation should have their thyroid-stimulating hormone (TSH) levels checked at least annually to screen for thyroid dysfunction. This specialized surveillance helps mitigate the long-term health consequences of past cancer treatment.