How effective is tamoxifen if taken early?

[Dgc12]

I noticed a sore left nipple two And a half years ago and after seeing the doctor and doing an ultrasound they diagnosed gynaecomastia but I didn't take the advised Tamoxifen 10 MG for six months as due to my background of having chemotherapy (for MS not cancer) I decided not to take the Tamo As it is a well-known carcinogen

As a result, now, two and a half years later the left side breast  has definitely grown but not so that it is  noticeable and I've spoken to Doctors who are not concerned by it
Probably because I'm skinny/underweight for my height

But I was just wondering, in hindsight, if the majority of patients take tamo when in the early stages of noticing either Soreness or enlarged tissue And then how effective it would be taking this drug for six months?

My doctor said at 10 MG for six months is not a concern regarding carcinogenic effects but I still refused to take as this is something I didn't want take a risk with

But is Tamo only effective when taken at the early stages of gyno?
Or do people ever take it Years later, for the first time, and saw reductions/benefit?
I just wanted to know why some people don't take tamo if they catch the gyno in the early Stages?
Is it because it is a carcinogenic drug? Or because inevitably the gyno will r ze  eturn? Even after taking six months of 10 MG Tamo.

I know this is all just opinions and not facts 

- I will upload photos as soon as the form allows me to as it keeps keeping me in error

[Evolver]

I am aware of 'Tamo' through researching the side effects of other hormone therapies for medical purposes. Although it is primarily a drug prescribed to people with breast cancer, it may also be prescribed to men to counteract gynecomastia that is induced by a LHRH agonist for example, in the treatment of prostate cancer.

I wouldn't know personally, but it must be effective for it to be a commonly recommended treatment. And if it actually caused cancer, it wouldn't be on the market.

What I do know about it, is that since it basically counteracts the effect of estrogen in your body, it will induce hot flashes. I would rather have breasts!

[Justagirl💃]

A CNA at the centre was prescribed Tamo after a double mastectomy due to breast cancer. 

Her main complaints are the constant hot flushes she feels and increase in belly fat (fat redistribution).

It does however prevent the estrogen craving cancer from spreading further thereby most likely saving her life during immunotherapy.