25% of cases of sarcomas, which are rare types of cancer, are incorrectly diagnosed

Accounting assistance is an example of an initial diagnostic difficulty that affected the course of her treatment. Her first symptom was heavy menstrual bleeding with loss of clots that did not stop and caused her severe pain. After consulting her gynecologist, she was diagnosed with uterine fibroids and recommended that the organ be removed. After the surgery, the pain disappeared and she said she felt relieved to be able to resume her routine. As usual, part of the uterus was sent for biopsy, and the result of the material was a surprise to everyone: it had a sarcoma, which was initially classified as low-grade.

“When I asked if this was cancer, the doctor shook his head and said yes. At that moment, I knew that at the age of 34, with two young children, I had a rare cancer, which accounts for less than 1% of cases. “I didn’t know,” Patricia says. Anyone with the same disease and my doctor didn't really know how to do the treatment, because it was so rare. But my faith is unwavering, no matter what the paper says.” A gynecologist referred her to start treatment with an oncologist in the public health system, at a cancer referral hospital in the interior of São Paulo.

But misclassification of her sarcoma type was precisely what hampered medical management and caused the cancer to progress rapidly. According to Roberto Pestana, clinical oncologist at Albert Einstein Israelita Hospital and researcher in the LACOG Sarcoma Group (Latin American Collaborative Group for Oncology), they are very rare tumors and there is little data available about this type of cancer in Brazil and in the world. However, there are still difficulties in diagnosis.

“This means that the history of these patients usually takes a long time between the initial symptoms and seeing a doctor. Then, due to the rarity of the tumors, the diagnosis of sarcoma is often not taken into account. And because they are rare tumors, when the test is sent for a biopsy, there is a risk of error: There are more than 100 types, often similar to each other under the microscope, and a definitive diagnosis may still depend on additional molecular tests, which is not the case everywhere, the oncologist explains.

According to Pestana, a delay in properly identifying the disease can cause the patient to lose critical time to control the disease. “Every step in this patient's journey is a challenge. Many people have never heard of sarcoma, so it's hard to even know where they can receive treatment,” he highlights.

With the diagnosis of low-grade sarcoma, Patricia was advised to simply monitor the progression of the disease. Between coming and going, I again felt severe abdominal pain and new tests showed small nodules in the lung, another in the abdomen, and another in the retroperitoneum, indicating the presence of metastases. She was then referred to the hospital's palliative care service and started on oral hormonal medications. “After starting treatment, the nodules doubled in size and she continued to be in incredible pain.”

Faced with a worsening of her clinical condition, the young woman decided to get a second opinion, repeated the tests and re-did the pathological analysis of the tumor and discovered that she had a sarcoma, but it was not a low-grade tumor – it was a high-grade tumor, stage IV (more aggressive and already advanced). A positron emission tomography (PET) scan showed more than 20 nodules in the lung alone. “I looked like a Dalmatian, with lots of black spots,” he says. It was necessary to completely change the treatment method, with immediate start of chemotherapy courses every 21 days. Five days after the onset of illness, symptoms improved. In the third cycle, the PET scan already showed a significant reduction in all nodules.