Hank Green of YouTube fame announced that he has Hodgkin lymphoma

Last week I posted a comparison of leukemia and lymphoma, two blood cancers involving white blood cells and their progenitors. Earlier in the week,  Hank Green, a YouTuber, author, and co-founder of VidCon (a conference of social media video stars), announced that he had been diagnosed with Hodgkin lymphoma (HL), the less common form of lymphoma (compared to non-Hodgkin lymphoma).

Mr. Green said he first noticed something was wrong when his armpit swelled unusually from enlarged lymph nodes. The most common symptoms of Hodgkin lymphoma are swelling of lymph nodes (in neck, armpits, or groin), fever, night sweats, persistent fatigue, and weight loss (Mayo Clinic). 

He went to a doctor for CT scans, an ultrasound, and a biopsy. These could confirm the diagnosis and determine the stage based on spread. Hodgkin lymphoma is staged from 1 to 4, with stage 1 being the least advanced and stage 4 being the most advanced. Stage 1 is limited to one lymph node region or structure, while stage 4 has spread beyond the lymphatic system (ACS). CT, PET, and ultrasound scans can ascertain this information. A biopsy of the lymph nodes or bone marrow is necessary to detect the presence of Reed-Sternberg cells, which are large abnormal multi-nucleate cells that originate from mature B-cells and are characteristic of HL.

Risk factors for Hodgkin lymphoma include infection by Epstein-Barr virus (EBV) which causes infectious mononucleosis (aka mono), family history, and a weakened immune system that can arise from HIV infection or an autoimmune disorder (ACS). In Mr. Green's case, he apparently had mononucleosis as a child, and currently has an autoimmune condition.

Leukemia and lymphoma are the most common cancers among children and young adults, although the risk is very low. HL is most common in young adults 15 to 39 (Mr. Green is 43), and in late adulthood (55 and older). 

The frontline treatment for Hodgkin lymphoma is chemotherapy or chemotherapy followed by radiation treatment if the cancer is sufficiently localized. There have been refinements of standard chemotherapy protocols such as developing more effective combinations. In addition, progress has been made on targeted therapies that specifically inhibit oncogenic proteins that drive certain forms of HL Finally, the two main types of immunotherapies, PD-1 inhibitors and CAR-T, have had success with both leukemias and lymphomas including HL.

The prognosis for Hodgkin lymphoma is good, with most patients going into remission after treatment.

For stage 1 the 5-year survival rate is ~95%, for stage 4 it is ~83%, and overall it is ~89% (ACS).  Mr. Green started the first round of chemotherapy last Friday, which will continue for at least four months. He is optimistic about his prognosis and stated that "the goal is cure."

As medicine continues its inexorable advance forward, we can count on even better treatments for Hodgkin lymphoma as well as other less treatable types of cancers, and survival rates will continue to climb.

Figure 1. YouTuber Hank Green announced last week that he has been diagnosed with Hodgkin lymphoma (CNN).