Backaches are common - nine out of 10 adults get them at some point in their lives. But little did Janice Lau, 47, expect that it would lead to the biggest health crisis of her life.
She had brushed the pain off as a common office worker ailment. But during an annual body check last August, tests showed elevated levels of serum globulin, a protein linked to antibodies.
Antibodies are produced by a type of white blood cell called a plasma cell to fight foreign objects such as bacteria and viruses. When a plasma cell becomes abnormal, it goes berserk and multiplies, producing an excess of their type-specific antibody, creating paraproteins. High globulin levels hint at the presence of paraproteins, which are a clue that cancer of the plasma cells - or plasma cell myeloma - may have taken root.
Additional tests confirmed the paraproteins in her blood.
She then sought the help of a specialist, Dr Raymond Liang, director of the Comprehensive Oncology Centre at the Hong Kong Sanatorium and Hospital.
He immediately ordered a bone marrow biopsy. Plasma cells are found mainly in the lymphoid organs, such as the spleen and lymph glands, but infiltrate and begin destroying the marrow when they become cancerous. Lau's marrow sample, extracted through a needle inserted into the hollow of the pelvic bone under local anaesthesia, contained a profusion of abnormal-looking plasma cells.
Next, an MRI (magnetic resonance imaging) scan was done. Plasma cells in the marrow erode the hard bone material, creating holes and causing pain. The scan revealed damage to many of her bones, and multiple lesions on her spine and pelvis. Also, her skull had a classic 'pepper pot' appearance - like the top of a pepper shaker.
The diagnosis was now undeniable, as she had all three classic symptoms of plasma cell myeloma.
Bone marrow destruction put her at risk of anaemia and a weakened immune system, and released excessive amounts of calcium that could lead to renal failure. The paraproteins also interfered with the production of normal antibodies, further depressing her immunity. By this time, Lau was also in severe pain.
Fortunately, her kidneys continued to function normally, and Liang set to work treating her in three phases.
First, she was put on a cocktail of drugs designed to destroy the abnormal plasma cells. This included weekly oral doses of dexamethasone, a steroid; intravenous injections of a new drug called bortezomib; and daily thalidomide pills to regulate the immune system.
The combination worked marvellously, with only minor side effects such as slight numbness in her fingers. After four months, Lau's blood was almost free of paraproteins, her bone marrow was emptied of plasma cells and the bone lesions were healing.
The second phase was to exterminate the abnormal plasma cells in a procedure called autologous hematopoietic stem cell transplantation. This involved harvesting her stem cells and freezing them, destroying all cells in the marrow using a chemotherapy drug, then 'rebooting' the marrow by repopulating it with the thawed stem cells. The transplant was a success. Three weeks later, Lau's bone marrow functioned normally.
In the final and continuing phase of treatment, Lau takes thalidomides to keep the cancer under control. She has returned to work in an accounting firm, and resumed her active lifestyle of cycling and jogging.
Chances of a cure for plasma cell myeloma are slim, Liang says. But given medical advances and Lau's relatively young age, the disease can be controlled for many years.