However, the simplest way to understand lymphoma is not as a single disease, but as a collection of many different but related ones. ‘Lymphoma’ is an umbrella term used for over 50 cancers. It is a group of blood cell tumours that affect the lymphatic system. There are two basic lymphoma categories: Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL).

“New treatments offer the possibility to improve cure rates in those cancers that are already curable; in diseases that remain incurable, like CLL, new treatments offer improved efficacy with less toxicity and longer remission rates.”

HL is a blood cancer that originates typically in lymphatic B cells and is categorized into four subtypes based upon the presence of Hodgkin and Reed-Sternberg (HRS) cells (cells characterized by larger or multiple nucleuses), and changes to cells surrounding them. Since cellular structure and behaviour in HL is different to that in NHL, the two are categorized differently. According to the Canadian Cancer Society, overall survival rates for HL are excellent, as HL is ‘very responsive to treatment.’

Understanding NHL

Understanding NHL is at first glance overwhelming. The sheer amount of differing types of NHL can seem confusing, but it is ultimately easy to navigate with the correct steps. At its most basic, NHL is divided into two categories — indolent NHL and aggressive NHL. In the former case, NHL is characterized by slow-growing tumours (low grade) and is a lifelong disease. Conversely, aggressive NHL is distinguished by fast-growing tumours (high grade). Early detection is essential in improving outcomes in aggressive NHL, with many patients achieving complete remission if the disease is found early enough.

Dr. John Kuruvilla is Staff Physician of Medical Oncology and Haematology at Princess Margaret Hospital in Toronto, and breaks down the complexity of NHL. “NHL is a series of over 30 different [cancer] types. It is understood by first identifying the type of cells from which the cancer originates and working from there. So, there are the two main types of NHL: B-Cell NHL, and T-Cell NHL. Within those spheres there are multiple different types so it’s not like saying ‘it’s one disease’, because the approaches to them are different. But the basic thing is that some are curable, some are not curable — and some require no treatment at all.”  

New therapies

Similarly to HL, NHL is mostly curable, with good survival rates. Treatment varies depending on the type of cancer present with typical options being chemotherapy, radiotherapy, surgery, biological therapies, and stem cell transplants. As with other cancers, recent advances in therapies have given renewed hope to many with lymphoma. “The new treatments offer the possibility to improve cure rates in those cancers that are already curable; in diseases that remain incurable, like CLL (Chronic Lymphocytic Leukemia), new treatments offer improved efficacy with less toxicity and longer remission rates,” says Dr. Kuruvilla.