Shannen Doherty has revealed she will need to be monitored more closely for signs that her breast cancer is back.
The 90210 star has been in remission for a year after a two-year-long battle with breast cancer.
On Tuesday Doherty, 46, shared a selfie on Instagram with the caption: ‘Test and results. One Tumor marker test came back good. Other… elevated.’
Tumor markers are substances in the blood that are typically higher in people with cancer and are often used to track the progression of the disease, but on their own are not reliable enough to be used in diagnosis.
We’ve broken down what the elevated level may mean for Doherty going forward.
Actress Shannon Doherty shared an update on her breast cancer battle on Instagram Tuesday revealing she’ll be monitored more closely after a test found elevated levels of a tumor marker
The 90210 star went into remission in April 2017 after a two-year battle with breast cancer
Shannen’s breast cancer battle
In August 2015 Doherty revealed she had been diagnosed with breast cancer that had spread to her lymph nodes, indicating it was either stage two or three.
The five-year survival rate for breast cancer is 93 percent at stage two and 72 percent at stage three, according to the American Society of Clinical Oncology (ASCO).
She had a mastectomy but the cancer was still present so she underwent chemotherapy and radiation.
In April 2017 she announced that she was in remission but that her fight may not be over.
There is a six percent chance of relapse in women with breast cancer that has spread to the lymph nodes who have undergone a mastectomy and radiation therapy, according to BreastCancer.org.
For the past year Doherty has been meeting with her doctors regularly for surveillance exams to detect any sign that the cancer has returned.
The 90s TV star is pictured left at gala in November 2015 just a few months after her cancer diagnosis was revealed and right at a Stand Up To Cancer event in September 2016
Doherty posted the photo above when she announced her remission on Instagram last year with the caption: ‘As every single one of my fellow cancer family knows, the next five years is crucial. Reoccurrences happen all the time’
This week’s setback
On its own, Doherty’s elevated tumor marker may not actually mean anything.
According to the ASCO: ‘In breast cancer care, three tumor markers have been used to help monitor metastatic breast cancer (advanced disease), but they have not been found to be useful to find a breast cancer recurrence or lengthen lives in patients who had early-stage breast cancer and who are now disease-free.’
Tumor markers are substances including proteins, enzymes, biochemicals or antigens that can be detected in higher than normal amounts in the blood, urine, or body tissues of some patients with certain types of cancer.
In breast cancer there are three antigens that can be used to monitor progression of a cancer or response to treatment.
However, tumor marker tests cannot be used to diagnose breast cancers on their own.
Doherty (pictured with her husband left and doctor right) had a mastectomy and underwent chemotherapy and radiation therapy
BreastCancer.org warns: ‘While breast cancer blood marker tests are promising, they’re not absolutely conclusive.
‘When a breast cancer blood marker test comes back negative, it doesn’t necessarily mean you’re free and clear of breast cancer. And a positive result doesn’t always mean that the cancer is growing.
‘These tests may help with diagnosis, but using cancer marker tests to find metastatic breast cancer hasn’t helped improve survival yet.’
Many health care providers don’t recommend running marker tests for patients in remission because they can lead to unnecessary anxiety.
Instead they recommend more reliable screening methods including physical exams, mammograms, bone health tests and pelvic exams.
Doherty is pictured in a congressional briefing for an animal rights’ bill in March 2017 weeks before announcing she had gone into remission
The possibility of recurrence
After an elevated tumor marker is detected, doctors will run other tests to look for signs of recurrence.
If none are found they may continue to monitor the marker for changes going forward.
In the Instagram post Tuesday Doherty said: ‘Just means I get monitored and another test.
‘But even after that call, I’m staying positive and taking stock of my life.
‘It certainly helps put things in perspective and reminds you of what you learned thru the cancer journey.’
Breast cancer can recur at the original site, called local recurrence, or it can return and spread to other parts of the body, called metastasis or distant recurrence.
I’m staying positive and taking stock of my life
Local recurrence is more common and is generally diagnosed using a mammogram or physical exam.
If a mastectomy wasn’t performed with the first cancer, it is typically the first treatment option for locally recurring cancers.
The second option is radiation therapy, which can also only be done if it wasn’t the first time.
Women like Doherty who have already had a mastectomy and radiation will typically be treated with chemotherapy, hormone therapy or targeted therapy.
Metastasis is usually found after symptoms are reported during follow-up appointments for patients in remission.
It is more common in women whose first cancer spread to other parts of the body such as the lymph nodes, like in Doherty’s case.
Distant recurrence can only be treated, not cured, typically with immunotherapy.
A 2008 study by researchers in Italy found that second cancers have a ten-year survival rate of 78 percent.
The chances of survival for second cancers was found to be between 30 and 50 percent higher when detected early.