<PAGE>
MASSACHUSETTS INVESTORS GROWTH STOCK FUND
Supplement to the Current Prospectus
During the period from February 2, 1998 through May 1, 1998 (unless
extended by MFS Fund Distributors, Inc. ("MFD")) (the "Sales Period"), MFD will
pay FSC Securities Corporation 100% of the applicable sales charge on sales of
Class A shares of the Fund sold by them during the Sales Period. In addition,
MFD will pay FSC Securities Corporation an additional commission equal to 0.50%
of the net asset value of all of the Class B shares of the Fund sold by them
during the Sales Period.
The date of this Supplement is February 2, 1998.
<PAGE>
MASSACHUSETTS INVESTORS GROWTH STOCK FUND
Supplement to the Current Prospectus
During the period from February 2, 1998 through May 1, 1998 (unless
extended by MFS Fund Distributors, Inc. ("MFD")) (the "Sales Period"), MFD will
pay Royal Alliance Associates 100% of the applicable sales charge on sales of
Class A shares of the Fund sold by them during the Sales Period. In addition,
MFD will pay Royal Alliance Associates an additional commission equal to 0.50%
of the net asset value of all of the Class B shares of the Fund sold by them
during the Sales Period.
The date of this Supplement is February 2, 1998.
<PAGE>
MASSACHUSETTS INVESTORS GROWTH STOCK FUND
Supplement to the Current Prospectus
During the period from February 2, 1998 through May 1, 1998 (unless
extended by MFS Fund Distributors, Inc. ("MFD")) (the "Sales Period"), MFD will
pay SunAmerica Securities, Inc. 100% of the applicable sales charge on sales of
Class A shares of the Fund sold by them during the Sales Period. In addition,
MFD will pay SunAmerica Securities, Inc. an additional commission equal to 0.50%
of the net asset value of all of the Class B shares of the Fund sold by them
during the Sales Period.
The date of this Supplement is February 2, 1998.
<PAGE>
MASSACHUSETTS INVESTORS GROWTH STOCK FUND
Supplement to the Current Prospectus
During the period from February 2, 1998 through May 1, 1998 (unless
extended by MFS Fund Distributors, Inc. ("MFD")) (the "Sales Period"), MFD will
pay Investment Management and Research, Inc. 100% of the applicable sales charge
on sales of Class A shares of the Fund sold by them during the Sales Period. In
addition, MFD will pay Investment Management and Research, Inc. an additional
commission equal to 0.50% of the net asset value of all of the Class B shares of
the Fund sold by them during the Sales Period.
The date of this Supplement is February 2, 1998.
<PAGE>
MASSACHUSETTS INVESTORS GROWTH STOCK FUND
Supplement to the Current Prospectus
During the period from February 2, 1998 through May 1, 1998 (unless
extended by MFS Fund Distributors, Inc. ("MFD")) (the "Sales Period"), MFD will
pay Advantage Capital Corporation 100% of the applicable sales charge on sales
of Class A shares of the Fund sold by them during the Sales Period. In addition,
MFD will pay Advantage Capital Corporation an additional commission equal to
0.50% of the net asset value of all of the Class B shares of the Fund sold by
them during the Sales Period.
The date of this Supplement is February 2, 1998.
<PAGE>
MASSACHUSETTS INVESTORS GROWTH STOCK FUND
Supplement to the Current Prospectus
During the period from February 2, 1998 through May 1, 1998 (unless
extended by MFS Fund Distributors, Inc. ("MFD")) (the "Sales Period"), MFD will
pay Mutual Service Corporation 100% of the applicable sales charge on sales of
Class A shares of the Fund sold by them during the Sales Period. In addition,
MFD will pay Mutual Service Corporation an additional commission equal to 0.50%
of the net asset value of all of the Class B shares of the Fund sold by them
during the Sales Period.
The date of this Supplement is February 2, 1998.
<PAGE>
MASSACHUSETTS INVESTORS GROWTH STOCK FUND
Supplement to the Current Prospectus
During the period from February 2, 1998 through May 1, 1998 (unless
extended by MFS Fund Distributors, Inc. ("MFD")) (the "Sales Period"), MFD will
pay Titon Value Equities Group, Inc. 100% of the applicable sales charge on
sales of Class A shares of the Fund sold by them during the Sales Period. In
addition, MFD will pay Titon Value Equities Group, Inc. an additional commission
equal to 0.50% of the net asset value of all of the Class B shares of the Fund
sold by them during the Sales Period.
The date of this Supplement is February 2, 1998.
