I had silicone implants in the 70s with no problems. Now I'm in my 70s am due a mammogram. Can my implants be left in?

The presence of the breast implant will not create health issues although if any silicone escapes the capsule surrounding the implant it can create a breast lump. This lump is not dangerous to your health but certainly can create uncertainty relative to the diagnosis of breast cancer. In the circumstances the implants as well as a capsule would be removed in combination with removal of the breast lump.

Radiologists have shown that they are able to see breast cancers via mammography or MRI even in the presence of breast implants. If there is a new lump, this should  be evaluated by a breast surgeon. Once you figure out the status of the breast lump, you can then make further decisions about the breast implants. Hopefully this lump turns out to be nothing of major concern, but one needs to be vigilant about such problems.

The important part first, any breast lump with or without implants requires a full investigation to rule out breast cancer. Next we can consider your implants, and as much as we know about them, it is very unlikely that your implants are intact and without a leak after 30+ years. You should expect calcification of the breast capsule on your mamogram and odds are replacement is in order if you wish to comfortabley keep them.