Vedic Astrology discusses about ‘Vrana Yoga‘ (Cancer disease) which is possible due to many planetary combinations and aspects in a horoscope.
General rule for Vrana Yoga is that, if 6th house lord is malefic (placed in nakshatra or constellation of 7th or 8th lord) and if it is placed in Ascendant, 8th house or 10th house, then Cancer disease is possible in Vimsottari Dasa of that planet.
This is most likely for people born in Gemini, Cancer, Leo, Virgo, Scorpio and Pisces ascendants.
If it is associated to ascendant, then it can lead to brain cancer.
Planets & Cancer causing areas in body
In general, Saturn is always linked with all diseases (especially chronic and long term) and if cancer causing planet is in anyway associated (conjunct, aspect, in constellation, in sign) with saturn, then cancer will take long time to cure.
Also if either Saturn or cancer causing planet are Retrograde in birth chart, the disease takes longer time to get cured.
Saturn and Rahu influencing second house (by placement or aspect) are main reason for tobacco chewing and smoking habits.
A person with these aspects should be careful and try to quit tobacco as it can lead to mouth, throat and lung cancer.
Houses & Cancer causing areas in body