Julian Walter This piece is part of our first-annual Health Care Heroes series, where we spotlight people doing amazing things in the health care and medical fields. Read the rest of the stories here . “IT’S LIKE FOUR Titanic ships sinking every week in the world.” Ash Tewari, MD, is describing a number that weighs on his heart a little bit. As a pioneer in robotic prostate cancer surgery and director of the Department of Urology at Mount Sinai in New York City, he spends his life in the operating room saving lives. But about five percent of the time, he says, “we feel we got to the patient a little too late. And that ‘too late’ usually happens because patients didn’t understand they could have prostate cancer .” This form of cancer, which affects roughly one in eight men, tends to quietly brew in the body. Guys don’t even think about getting screened for it because they feel healthy.…