Experts are using World Cancer Day, tomorrow, to step up their message that people must become more aware of symptoms that could signal early cancer and report them to their GPs - which could save their life. Most cancers are curable if caught in the early stages, says David Bloomfield, clinical oncologist at the Sussex Cancer Centre."Be aware of the red flags [below], but if something else is unexplained and unusual for you and doesn't get better in a couple of weeks, get it checked out."Hoarseness or croaky voiceBeing croaky or hoarse is common with a cold, but if it doesn't get better within two or three weeks, it needs checking out.Heavy night sweatsHeavy night sweats could be a sign of lymphoma, a tumour developing in the lymph cells. Other symptoms may include a lump about 2cm or more in diameter in the armpit, groin or side of the neck.Persistent heartburnIt's not unusual to feel pain or discomfort after a fatty or spicy meal, but if this has lasted more than two or three weeks, it could signal cancer of the stomach or oesophagus, or it may be a sign of pancreatic or ovarian cancer.Middle-back painBack pain is also one of the more common symptoms of pancreatic cancer.Pink discharge after menopausePink discharge from subtle bleeding - or any kind of vaginal bleeding after menopause - can be an early sign of endometrial cancer.Problems urinatingFrequent urination or problems urinating could indicate prostate cancer.Difficulty swallowingOccasionally, it may be a key early symptom of a head or neck cancer such as of the vocal cords, oesophagus, mouth or tongue.Looser stoolsThis may indicate bowel cancer.A sore that won't healSmall lumps on the skin that get bigger could be a sign of skin cancer. ..