Researchers from University College London have found that in around one in six cases of (17 percent) breast cancer the first symptoms that present are not a lump in the breast.
Crucially, their findings, presented at the 2016 National Cancer Research Institute (NCRI) Cancer conference in Liverpool, show that women with non-lump symptoms of breast cancer are more likely to delay going to their doctor than those with a breast lump alone, thus risking a later diagnosis.
The research, which looked at the data of more than 2,300 women diagnosed with breast cancer in England in 2009/10, also found that women with both a breast lump and 'non-lump' symptoms were also more likely to delay seeking help.
"Our research shows around one in six women diagnosed with breast cancer have symptoms other than a breast lump, [and] these women are more likely to delay going to the doctor compared to women with breast lump alone" said Monica Koo, presenting author based at UCL, stressing: "It's crucial that women are aware that a lump is not the only symptom of breast cancer".
Others potential symptoms of the disease include nipple abnormalities, breast pain, skin abnormalities, ulceration, shape abnormalities and an infected or inflamed breast.
Currently more than 53,600 women are diagnosed with breast cancer every year, and the earlier the detection the better the chance of survival.
"This research shows that, all too often, women are delaying going to their doctor with symptoms of breast cancer," said Dr Karen Kennedy, Director of the NCRI. "With a disease like breast cancer, it's essential to be diagnosed as early as possible so that a treatment plan can be developed and started".
Experts are now calling for campaigns to raise awareness of all symptoms of the disease.