12/16 "The Beal Method" Optimizing Breast Development in Trans and Gender Diverse People

There is no one way to be trans. Not every trans person interested in estrogen is also interested in breast development. Further, this discussion sits at the intersection of gender dysphoria and patriarchal, misogynistic, white supremacist ideal standards of beauty. Acknowledging the complexity of all of that, some folx want to try and optimize breast development. Literature supports that somewhere between 50-66% of folx who take estrogen are dissatisfied with breast development and seek breast augmentation.^{1, 2} Research indicates the median breast development in gender diverse folx on estrogen is reported to be 19 cm, which is very close in size to the median in cis women.¹ However, this often equates to an A cup because cup size is affected by band size. Bodies that went through a first puberty with testosterone tend to have wider and broader chests which means their band size is bigger. Ultimately, even though trans folx on estrogen tend to have close to the same volume of breast tissues as cis women, it sits on a larger chest making it look proportionally smaller. 

So you may wonder if there are ways to optimize breast development through hormonal treatment?

To be frank, we don’t fully understand breast development or all of the factors that contribute to it, even in cis females, despite more money and effort dedicated to research for cis folx than for trans folx. Research in trans folx is even more sparse. Breast development seems to pass through similar phases in trans folx as cis folx; however, it is not identical. The following proposal is all based in theory not in evidence and may be incongruent with access or other individual goals of care. Please keep that in mind.

We do know estradiol and progesterone are essential for the development of mature breasts. Additionally, IGF-1 (insulin like growth factor 1) and GH (growth hormone) contribute to breast development. IGF-1 does increase in response to the estrogen and progesterone that trans folx take, but growth hormone does not. One study found that progesterone does not benefit breast development³, but it only looked at a 3-month time frame. An older study that looked out to 6 and 9 months found benefit to breast development from progesterone⁴. Both of these studies were small, with 23-29 participants each. A larger systematic review found that we need more information⁵.

What we do know about breast development in trans and gender diverse folx is that higher doses of estrogen earlier in treatment seem to lead to less volume of breast development overall^{6, 7} and spironolactone use is associated with a small but statistically significant increase in seeking breast augmentation⁶. In cis adolescents, thelarche, or breast development, is about a 4-year process that starts with relatively low levels of estradiol that increase gradually over time. Progesterone production starts a little later than estrogen in this process. Some clinicians (Dr. Beal included,) have theorized that to optimize breast development in trans and gender diverse folx, we need to very effectively turn off testosterone production and use low levels of estradiol for longer periods of time in early treatment. The team at QueerDoc have jokingly called this, “The Beal Method.” It would look something like treatment with a GnRH agonist or orchiectomy prior to starting estradiol. Then the addition of estradiol, ideally transdermally with patches, gel, or cream at low levels to replicate the levels seen in early endogeonous puberty – Tanner Stage II (no more than 24pg/mL; although this varies a bit by lab facility) for about a year. During this year levels would gradually increase overtime. At the year mark, target estradiol levels would be no more than 60pg/mL to replicate Tanner Stage III. Then, maintain estradiol levels at a Tanner Stage III level for about a year with gradual escalation of dose over time. The third year of treatment would reflect Tanner Stage IV levels of up to 85pg/mL with doses also increasing gradually over time. After the third year, maintenance dosing would be recommended to replicate Tanner Stage V with levels between 100-300pg/mL. Incremental dose increases at 6-month intervals can mimic the normal pubertal tempo until adult dosing is reached over 3 years. This theoretically translates into a 25% to 100% increase in dose every 6 months.

Progesterone would be added about 1.5 years into the treatment protocol replicating the timing in cis adolescent females. Progesterone levels are usually low in cis females until the onset of periods (menarche) which occurs on average 1.5-3 years after the start of breast development. During this time adequate rest and calories would be advised: the trope of teenagers sleeping and eating all of the time is based in the reality that puberty is a time of high energy needs for the body. Creating new tissue is demanding! Additionally, puberty is a time of weight gain. There may be some benefit to a modest gain of about 5-8lbs during the first 3 years of treatment.

You may have noticed “The Beal Method” proposed above doesn’t include growth hormone. Research in people with Turner’s Syndrome, a difference in sex development, found they reported more satisfaction with breast development if they had been treated with growth hormone⁸. However, growth hormone treatment in Turner’s Syndrome is focused on height development, so dosing strategies aren’t applicable to gender affirming care for adults trying to optimize breast development. I, (Dr. Beal here,) do believe that in the future I may modify “my method” with the addition of growth hormone but as of yet have not determined the following:

• What the risk/benefit ratio of adding growth hormone is
• Appropriate dosing
• Appropriate timing
• Appropriate monitoring

“The Beal Method” isn’t a perfect table or protocol because every person treated would need to be monitored with labs and dose titration would be in response to individual hormone levels and Tanner staging of breast development. Therefore the dosing levels in the treatment column might not be entirely accurate. However a rough outline would look like:

*may use bicalutamide or dutasteride through initial 2 week surge of testosterone with GnRH agonist to prevent worsening dysphoria

Ultimately, at QueerDoc, we believe gender affirming care should be individualized to each person’s goals, health, values, and access. GnRH agonists are expensive and are often hard to access in the United States. Buserelin can be ordered from international pharmacies for folx who have higher risk tolerance. Similarly, orchiectomy, which is an irreversible surgery, might not be the best fit for folx, especially early in gender affirming care. Both orchiectomy and GnRH agonists have a tendency to significantly decrease or entirely stop erections which might not align with the person’s goals. The method proposed above is all theoretical: there is no evidence behind it or research saying it is more effective. Gender affirming care is not one size fits all and there is no one best way – it is highly individualized. This is just the musing of a gender diverse doctor who does this work all day, everyday.

References

1. Seal LJ, Franklin S, Richards C, Shishkareva A, Sinclaire C, Barrett J. Predictive markers for mammoplasty and a comparison of side effect profiles in transwomen taking various hormonal regimens. J Clin Endocrinol Metab. 2012;97(12):4422-4428. doi:10.1210/jc.2012-2030
2. Berliere M, Coche M, Lacroix C, et al. Effects of Hormones on Breast Development and Breast Cancer Risk in Transgender Women. Cancers (Basel). 2022;15(1):245. Published 2022 Dec 30. doi:10.3390/cancers15010245
3. Nolan BJ, Frydman AS, Leemaqz SY, Carroll M, Grossmann M, Zajac JD, Cheung AS. Effects of low-dose oral micronised progesterone on sleep, psychological distress, and breast development in transgender individuals undergoing feminising hormone therapy: a prospective controlled study. Endocr Connect. 2022 May 23;11(5):e220170. doi: 10.1530/EC-22-0170. PMID: 35521814; PMCID: PMC9175584.
4. Bahr C, Ewald J, Dragovich R, Gothard MD. Effects of progesterone on gender affirmation outcomes as part of feminizing hormone therapy. J Am Pharm Assoc (2003). 2023 Aug 5:S1544-3191(23)00252-2. doi: 10.1016/j.japh.2023.08.001. Epub ahead of print. PMID: 37549733.
5. Patel KT, Adeel S, Rodrigues Miragaya J, Tangpricha V. Progestogen Use in Gender-Affirming Hormone Therapy: A Systematic Review. Endocr Pract. 2022 Dec;28(12):1244-1252. doi: 10.1016/j.eprac.2022.08.012. Epub 2022 Aug 23. PMID: 36007714.
6. Seal LJ, Franklin S, Richards C, Shishkareva A, Sinclaire C, Barrett J. Predictive markers for mammoplasty and a comparison of side effect profiles in transwomen taking various hormonal regimens. J Clin Endocrinol Metab. 2012;97(12):4422-4428. doi:10.1210/jc.2012-2030
7. Seal LJ. A review of the physical and metabolic effects of cross-sex hormonal therapy in the treatment of gender dysphoria. Ann Clin Biochem. 2016 Jan;53(Pt 1):10-20. doi: 10.1177/0004563215587763. Epub 2015 May 1. PMID: 25933804.
8. van de Grift TC, Kreukels BPC; dsd-LIFE. Breast development and satisfaction in women with disorders/differences of sex development. Hum Reprod. 2019 Dec 1;34(12):2410-2417. doi: 10.1093/humrep/dez230. PMID: 31774116; PMCID: PMC6936743.