Osteogenic sarcoma: Nagging limb pain in children could signal deadly bone cancer

Pain in a child’s limb is often treated as a minor issue, dismissed as the result of a fall, a sports injury, or ordinary growth. Swelling around the knee or persistent limping may prompt short-term medication, rest, or reassurance that the problem will resolve on its own. But medical experts warn that when such symptoms persist, especially in children and adolescents, they may indicate a far more serious condition.

“Osteogenic sarcoma is a disease that mainly affects children and teenagers,” says Dr Wattanga Lilac, a Consultant Clinical and Radiation Oncologist working in Kisumu County. “It is mostly found in the long bones, especially the lower limbs around the knee, the legs, and sometimes the arms.”

According to Dr Lilac, most patients seen in oncology clinics are underage, and many present with symptoms that have been present for weeks or months.

“Most of them are very young,” she explains. “They usually come with a parent who gives a history of maybe a fall, and then the leg started swelling. In other cases, the parent reports that the leg had been swelling for some time and the child had been limping at home.”

These early symptoms, she notes, are commonly mistaken for injuries or infections, leading to delays in referral and diagnosis.

Affected bones

Osteogenic sarcoma usually develops in areas of rapid bone growth. The most affected sites, include the distal femur just above the knee, the proximal tibia below the knee, and the humerus in the upper arm.

“The child may complain of pain that does not go away,” Dr Lilac says. “At first it may come and go, but later it becomes persistent.”

Swelling may gradually increase, and movement of the affected limb may become restricted. In some cases, the child develops a noticeable limp.

“These are the cases that we see most often,” she explains. “And unfortunately, many of them present late.”

Diagnosis of osteogenic sarcoma follows a structured clinical pathway, often beginning at peripheral health facilities. “The first thing that is done is an X-ray. This is usually performed at a nearby facility,” Dr Lilac says. 

On the X-ray, clinicians may observe abnormal bone changes that raise suspicion of malignancy. “The X-ray may show what we describe as a sunburst or abnormal appearance of the bone,” she explains. Once suspicion is raised, the patient is referred to an orthopaedic specialist.

“From there, the patient goes to the orthopaedic department. That is where a biopsy is done,” Dr Lilac says.

The biopsy, she emphasises, is essential. “Without a biopsy, you cannot confirm someone has cancer. Once the biopsy confirms osteogenic sarcoma, the patient is referred to us as oncologists.”

After histological confirmation, the next critical step is staging. “We confirm the diagnosis with histology, inform the patient and the family, and then perform a CT scan to stage the illness,” she explains.

Staging determines how far the cancer has spread and guides treatment planning. “Our main concern is staging. Because once we know the stage, we can plan the treatment,” Dr Lilac says. 

CT scans of the chest are particularly important, as the lungs are the most common site of metastasis. Imaging of the affected limb is also carried out to assess the local extent of the disease.

Surgical options vary depending on the extent of disease. In some cases, limb-sparing surgery is possible. In others, amputation may be required to fully remove the tumour.

“Our priority is always the life of the child. Limb preservation is important, but complete removal of the cancer is the most important thing,” Dr Lilac says. 

After surgery, chemotherapy continues to eliminate any remaining cancer cells. In selected cases, radiotherapy may also be considered.

“As an oncologist, you have to decide whether palliative chemotherapy is necessary. This is after discussing the benefits and expected outcomes with the family,” Dr Lilac says. 

Osteogenic sarcoma is not among the most common cancers, but its impact is significant because of the age group it affects.

“Osteogenic sarcoma is not easy to diagnose. It is not easy to prevent, and it is not easy to detect early,” adds Pamela Were, an Independent Oncology Consultant affiliated with the International Cancer Institute. 

However, she emphasises that awareness and clinical suspicion can make a difference.

“With good training and a high index of suspicion, it is possible to suspect it earlier. Especially when a young person keeps presenting with joint pain, in the knee, hip, or shoulder,” Were says.

She explains that repeated pain without a clear cause should never be ignored.

“If someone keeps complaining of pain in the same area, that is something that needs further investigation,” she says.

Treatment challenges

Even when patients seek care early, delays within the health system often slow diagnosis and treatment.

After a biopsy, the sample must be analysed in a histopathology laboratory. “These labs are not available everywhere. Samples may have to be sent far, and that takes time,” she explains. 

Imaging services pose another challenge. “You may need a CT scan or MRI, but those services may not be available locally, so the patient has to be referred,” Were says.

Each referral adds time, and during that time, the disease continues to progress. “Cancer cells do not wait,” she adds.

Financial constraints further complicate cancer care. “Some patients do not have insurance and cannot afford the costs,” Were explains.

Even when diagnosis is confirmed, treatment may be delayed due to cost. “By the time treatment starts, the disease may have already advanced,” she says.

There is still widespread belief that cancer is a death sentence. “People think cancer means death. That belief exists because of late diagnosis,” Were says. 

Asked about gaps in cancer care, Dr Lilac points to late diagnosis and limited awareness. “Our main gaps are late diagnosis and lack of screening,” she says.

Were adds that staffing shortages and limited specialised services affect quality of care. “When there are many patients and few trained staff, quality of care is compromised,” she says.

Despite the challenges, both experts stress that osteogenic sarcoma is not hopeless.

“There is hope. Something can always be done to improve quality of life,” Were says. 

Dr Lilac underscores the importance of early action. “The faster we act, the better the outcome. Pain, swelling, and limping in children should never be ignored,” she says.