import re
text = "there are many people in the world having colorectal cancer (crc) who also have the depression syndrome (ds)"
acrolen=5
rt=[]
acronym_list = ["(crc)", "(ds)"]
for acro in acronym_list:
p = r'(?:\w+\W+){1,%d}%s' %(acrolen, re.escape(acro))
find_words= re.findall(p, text, re.I)
for word in find_words:
rt.append(word)
print rt
aW1wb3J0IHJlCnRleHQgPSAidGhlcmUgYXJlIG1hbnkgcGVvcGxlIGluIHRoZSB3b3JsZCBoYXZpbmcgY29sb3JlY3RhbCBjYW5jZXIgKGNyYykgd2hvIGFsc28gaGF2ZSB0aGUgZGVwcmVzc2lvbiBzeW5kcm9tZSAoZHMpIgphY3JvbGVuPTUKcnQ9W10KYWNyb255bV9saXN0ID0gWyIoY3JjKSIsICIoZHMpIl0KZm9yIGFjcm8gaW4gYWNyb255bV9saXN0OgoJcCA9IHInKD86XHcrXFcrKXsxLCVkfSVzJyAgJShhY3JvbGVuLCByZS5lc2NhcGUoYWNybykpCglmaW5kX3dvcmRzPSByZS5maW5kYWxsKHAsIHRleHQsIHJlLkkpCglmb3Igd29yZCBpbiBmaW5kX3dvcmRzOgoJCXJ0LmFwcGVuZCh3b3JkKQpwcmludCBydA==